ilyakooo0/nixpkgs
1
0
Fork 0
mirror of https://github.com/ilyakooo0/nixpkgs.git synced 2024-12-26 04:43:09 +03:00
Code Issues Projects Releases Wiki Activity

nixpkgs docs: format =)

Browse Source
This commit is contained in:
Graham Christensen 2018-05-01 19:54:21 -04:00
parent fd2dce9708
commit 77161de454
No known key found for this signature in database
GPG Key ID: ACA1C1D120C83D5C
27 changed files with 8153 additions and 6710 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1218
doc/coding-conventions.xml
View File

File diff suppressed because it is too large Load Diff

559
doc/configuration.xml
View File

@ -1,42 +1,51 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-packageconfig">
<title>Global configuration</title>
<para>Nix comes with certain defaults about what packages can and
cannot be installed, based on a package's metadata. By default, Nix
will prevent installation if any of the following criteria are
true:</para>
<itemizedlist>
<listitem><para>The package is thought to be broken, and has had
its <literal>meta.broken</literal> set to
<literal>true</literal>.</para></listitem>
<listitem><para>The package isn't intended to run on the given system, as none of its <literal>meta.platforms</literal> match the given system.</para></listitem>
<listitem><para>The package's <literal>meta.license</literal> is set
to a license which is considered to be unfree.</para></listitem>
<listitem><para>The package has known security vulnerabilities but
has not or can not be updated for some reason, and a list of issues
has been entered in to the package's
<literal>meta.knownVulnerabilities</literal>.</para></listitem>
</itemizedlist>
<para>Note that all this is checked during evaluation already,
and the check includes any package that is evaluated.
In particular, all build-time dependencies are checked.
<literal>nix-env -qa</literal> will (attempt to) hide any packages
that would be refused.
</para>
<para>Each of these criteria can be altered in the nixpkgs
configuration.</para>
<para>The nixpkgs configuration for a NixOS system is set in the
<literal>configuration.nix</literal>, as in the following example:
<title>Global configuration</title>
<para>
Nix comes with certain defaults about what packages can and cannot be
installed, based on a package's metadata. By default, Nix will prevent
installation if any of the following criteria are true:
</para>
<itemizedlist>
<listitem>
<para>
The package is thought to be broken, and has had its
<literal>meta.broken</literal> set to <literal>true</literal>.
</para>
</listitem>
<listitem>
<para>
The package isn't intended to run on the given system, as none of its
<literal>meta.platforms</literal> match the given system.
</para>
</listitem>
<listitem>
<para>
The package's <literal>meta.license</literal> is set to a license which is
considered to be unfree.
</para>
</listitem>
<listitem>
<para>
The package has known security vulnerabilities but has not or can not be
updated for some reason, and a list of issues has been entered in to the
package's <literal>meta.knownVulnerabilities</literal>.
</para>
</listitem>
</itemizedlist>
<para>
Note that all this is checked during evaluation already, and the check
includes any package that is evaluated. In particular, all build-time
dependencies are checked. <literal>nix-env -qa</literal> will (attempt to)
hide any packages that would be refused.
</para>
<para>
Each of these criteria can be altered in the nixpkgs configuration.
</para>
<para>
The nixpkgs configuration for a NixOS system is set in the
<literal>configuration.nix</literal>, as in the following example:
<programlisting>
{
nixpkgs.config = {
@ -44,187 +53,197 @@ configuration.</para>
};
}
</programlisting>
However, this does not allow unfree software for individual users.
Their configurations are managed separately.</para>
<para>A user's of nixpkgs configuration is stored in a user-specific
configuration file located at
<filename>~/.config/nixpkgs/config.nix</filename>. For example:
However, this does not allow unfree software for individual users. Their
configurations are managed separately.
</para>
<para>
A user's of nixpkgs configuration is stored in a user-specific configuration
file located at <filename>~/.config/nixpkgs/config.nix</filename>. For
example:
<programlisting>
{
allowUnfree = true;
}
</programlisting>
</para>
<para>Note that we are not able to test or build unfree software on Hydra
due to policy. Most unfree licenses prohibit us from either executing or
distributing the software.</para>
<section xml:id="sec-allow-broken">
</para>
<para>
Note that we are not able to test or build unfree software on Hydra due to
policy. Most unfree licenses prohibit us from either executing or
distributing the software.
</para>
<section xml:id="sec-allow-broken">
<title>Installing broken packages</title>
<para>There are two ways to try compiling a package which has been
marked as broken.</para>
<para>
There are two ways to try compiling a package which has been marked as
broken.
</para>
<itemizedlist>
<listitem><para>
For allowing the build of a broken package once, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_BROKEN=1</programlisting>
</para></listitem>
<listitem><para>
For permanently allowing broken packages to be built, you may
add <literal>allowBroken = true;</literal> to your user's
configuration file, like this:
<listitem>
<para>
For allowing the build of a broken package once, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_BROKEN=1</programlisting>
</para>
</listitem>
<listitem>
<para>
For permanently allowing broken packages to be built, you may add
<literal>allowBroken = true;</literal> to your user's configuration file,
like this:
<programlisting>
{
allowBroken = true;
}
</programlisting>
</para></listitem>
</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="sec-allow-unsupported-system">
</section>
<section xml:id="sec-allow-unsupported-system">
<title>Installing packages on unsupported systems</title>
<para>
There are also two ways to try compiling a package which has been marked as unsuported for the given system.
There are also two ways to try compiling a package which has been marked as
unsuported for the given system.
</para>
<itemizedlist>
<listitem><para>
For allowing the build of a broken package once, you can use an environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1</programlisting>
</para></listitem>
<listitem>
<para>
For permanently allowing broken packages to be built, you may add <literal>allowUnsupportedSystem = true;</literal> to your user's configuration file, like this:
<listitem>
<para>
For allowing the build of a broken package once, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1</programlisting>
</para>
</listitem>
<listitem>
<para>
For permanently allowing broken packages to be built, you may add
<literal>allowUnsupportedSystem = true;</literal> to your user's
configuration file, like this:
<programlisting>
{
allowUnsupportedSystem = true;
}
</programlisting>
</para>
</listitem>
</para>
</listitem>
</itemizedlist>
<para>
The difference between an a package being unsupported on some system and being broken is admittedly a bit fuzzy.
If a program <emphasis>ought</emphasis> to work on a certain platform, but doesn't, the platform should be included in <literal>meta.platforms</literal>, but marked as broken with e.g. <literal>meta.broken = !hostPlatform.isWindows</literal>.
Of course, this begs the question of what "ought" means exactly.
That is left to the package maintainer.
The difference between an a package being unsupported on some system and
being broken is admittedly a bit fuzzy. If a program
<emphasis>ought</emphasis> to work on a certain platform, but doesn't, the
platform should be included in <literal>meta.platforms</literal>, but marked
as broken with e.g. <literal>meta.broken =
!hostPlatform.isWindows</literal>. Of course, this begs the question of what
"ought" means exactly. That is left to the package maintainer.
</para>
</section>
<section xml:id="sec-allow-unfree">
</section>
<section xml:id="sec-allow-unfree">
<title>Installing unfree packages</title>
<para>There are several ways to tweak how Nix handles a package
which has been marked as unfree.</para>
<para>
There are several ways to tweak how Nix handles a package which has been
marked as unfree.
</para>
<itemizedlist>
<listitem><para>
To temporarily allow all unfree packages, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_UNFREE=1</programlisting>
</para></listitem>
<listitem><para>
It is possible to permanently allow individual unfree packages,
while still blocking unfree packages by default using the
<literal>allowUnfreePredicate</literal> configuration
option in the user configuration file.</para>
<para>This option is a function which accepts a package as a
parameter, and returns a boolean. The following example
configuration accepts a package and always returns false:
<listitem>
<para>
To temporarily allow all unfree packages, you can use an environment
variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_UNFREE=1</programlisting>
</para>
</listitem>
<listitem>
<para>
It is possible to permanently allow individual unfree packages, while
still blocking unfree packages by default using the
<literal>allowUnfreePredicate</literal> configuration option in the user
configuration file.
</para>
<para>
This option is a function which accepts a package as a parameter, and
returns a boolean. The following example configuration accepts a package
and always returns false:
<programlisting>
{
allowUnfreePredicate = (pkg: false);
}
</programlisting>
</para>
<para>A more useful example, the following configuration allows
only allows flash player and visual studio code:
</para>
<para>
A more useful example, the following configuration allows only allows
flash player and visual studio code:
<programlisting>
{
allowUnfreePredicate = (pkg: elem (builtins.parseDrvName pkg.name).name [ "flashplayer" "vscode" ]);
}
</programlisting>
</para></listitem>
<listitem>
<para>It is also possible to whitelist and blacklist licenses
that are specifically acceptable or not acceptable, using
<literal>whitelistedLicenses</literal> and
<literal>blacklistedLicenses</literal>, respectively.
</para>
<para>The following example configuration whitelists the
licenses <literal>amd</literal> and <literal>wtfpl</literal>:
</para>
</listitem>
<listitem>
<para>
It is also possible to whitelist and blacklist licenses that are
specifically acceptable or not acceptable, using
<literal>whitelistedLicenses</literal> and
<literal>blacklistedLicenses</literal>, respectively.
</para>
<para>
The following example configuration whitelists the licenses
<literal>amd</literal> and <literal>wtfpl</literal>:
<programlisting>
{
whitelistedLicenses = with stdenv.lib.licenses; [ amd wtfpl ];
}
</programlisting>
</para>
<para>The following example configuration blacklists the
<literal>gpl3</literal> and <literal>agpl3</literal> licenses:
</para>
<para>
The following example configuration blacklists the <literal>gpl3</literal>
and <literal>agpl3</literal> licenses:
<programlisting>
{
blacklistedLicenses = with stdenv.lib.licenses; [ agpl3 gpl3 ];
}
</programlisting>
</para>
</listitem>
</para>
</listitem>
</itemizedlist>
<para>A complete list of licenses can be found in the file
<filename>lib/licenses.nix</filename> of the nixpkgs tree.</para>
</section>
<para>
A complete list of licenses can be found in the file
<filename>lib/licenses.nix</filename> of the nixpkgs tree.
</para>
</section>
<section xml:id="sec-allow-insecure">
<title>Installing insecure packages</title>
<section xml:id="sec-allow-insecure">
<title>
Installing insecure packages
</title>
<para>There are several ways to tweak how Nix handles a package
which has been marked as insecure.</para>
<para>
There are several ways to tweak how Nix handles a package which has been
marked as insecure.
</para>
<itemizedlist>
<listitem><para>
To temporarily allow all insecure packages, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_INSECURE=1</programlisting>
</para></listitem>
<listitem><para>
It is possible to permanently allow individual insecure
packages, while still blocking other insecure packages by
default using the <literal>permittedInsecurePackages</literal>
configuration option in the user configuration file.</para>
<para>The following example configuration permits the
installation of the hypothetically insecure package
<literal>hello</literal>, version <literal>1.2.3</literal>:
<listitem>
<para>
To temporarily allow all insecure packages, you can use an environment
variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_INSECURE=1</programlisting>
</para>
</listitem>
<listitem>
<para>
It is possible to permanently allow individual insecure packages, while
still blocking other insecure packages by default using the
<literal>permittedInsecurePackages</literal> configuration option in the
user configuration file.
</para>
<para>
The following example configuration permits the installation of the
hypothetically insecure package <literal>hello</literal>, version
<literal>1.2.3</literal>:
<programlisting>
{
permittedInsecurePackages = [
@ -232,47 +251,44 @@ distributing the software.</para>
];
}
</programlisting>
</para>
</listitem>
<listitem><para>
It is also possible to create a custom policy around which
insecure packages to allow and deny, by overriding the
<literal>allowInsecurePredicate</literal> configuration
option.</para>
<para>The <literal>allowInsecurePredicate</literal> option is a
function which accepts a package and returns a boolean, much
like <literal>allowUnfreePredicate</literal>.</para>
<para>The following configuration example only allows insecure
packages with very short names:
</para>
</listitem>
<listitem>
<para>
It is also possible to create a custom policy around which insecure
packages to allow and deny, by overriding the
<literal>allowInsecurePredicate</literal> configuration option.
</para>
<para>
The <literal>allowInsecurePredicate</literal> option is a function which
accepts a package and returns a boolean, much like
<literal>allowUnfreePredicate</literal>.
</para>
<para>
The following configuration example only allows insecure packages with
very short names:
<programlisting>
{
allowInsecurePredicate = (pkg: (builtins.stringLength (builtins.parseDrvName pkg.name).name) &lt;= 5);
}
</programlisting>
</para>
<para>Note that <literal>permittedInsecurePackages</literal> is
only checked if <literal>allowInsecurePredicate</literal> is not
specified.
</para></listitem>
</para>
<para>
Note that <literal>permittedInsecurePackages</literal> is only checked if
<literal>allowInsecurePredicate</literal> is not specified.
</para>
</listitem>
</itemizedlist>
</section>
</section>
<!--============================================================-->
<section xml:id="sec-modify-via-packageOverrides">
<title>Modify packages via <literal>packageOverrides</literal></title>
<section xml:id="sec-modify-via-packageOverrides"><title>Modify
packages via <literal>packageOverrides</literal></title>
<para>You can define a function called
<varname>packageOverrides</varname> in your local
<filename>~/.config/nixpkgs/config.nix</filename> to override nix packages. It
must be a function that takes pkgs as an argument and return modified
set of packages.
<para>
You can define a function called <varname>packageOverrides</varname> in your
local <filename>~/.config/nixpkgs/config.nix</filename> to override nix
packages. It must be a function that takes pkgs as an argument and return
modified set of packages.
<programlisting>
{
packageOverrides = pkgs: rec {
@ -280,30 +296,27 @@ set of packages.
};
}
</programlisting>
</para>
</section>
<section xml:id="sec-declarative-package-management">
</para>
</section>
<section xml:id="sec-declarative-package-management">
<title>Declarative Package Management</title>
<section xml:id="sec-building-environment">
<title>Build an environment</title>
<title>Build an environment</title>
<para>
Using <literal>packageOverrides</literal>, it is possible to manage
packages declaratively. This means that we can list all of our desired
packages within a declarative Nix expression. For example, to have
<literal>aspell</literal>, <literal>bc</literal>,
<literal>ffmpeg</literal>, <literal>coreutils</literal>,
<literal>gdb</literal>, <literal>nixUnstable</literal>,
<literal>emscripten</literal>, <literal>jq</literal>,
<literal>nox</literal>, and <literal>silver-searcher</literal>, we could
use the following in <filename>~/.config/nixpkgs/config.nix</filename>:
</para>
<para>
Using <literal>packageOverrides</literal>, it is possible to manage
packages declaratively. This means that we can list all of our desired
packages within a declarative Nix expression. For example, to have
<literal>aspell</literal>, <literal>bc</literal>,
<literal>ffmpeg</literal>, <literal>coreutils</literal>,
<literal>gdb</literal>, <literal>nixUnstable</literal>,
<literal>emscripten</literal>, <literal>jq</literal>,
<literal>nox</literal>, and <literal>silver-searcher</literal>, we could
use the following in <filename>~/.config/nixpkgs/config.nix</filename>:
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; {
myPackages = pkgs.buildEnv {
@ -314,17 +327,17 @@ set of packages.
}
</screen>
<para>
To install it into our environment, you can just run <literal>nix-env -iA
nixpkgs.myPackages</literal>. If you want to load the packages to be built
from a working copy of <literal>nixpkgs</literal> you just run
<literal>nix-env -f. -iA myPackages</literal>. To explore what's been
installed, just look through <filename>~/.nix-profile/</filename>. You can
see that a lot of stuff has been installed. Some of this stuff is useful
some of it isn't. Let's tell Nixpkgs to only link the stuff that we want:
</para>
<para>
To install it into our environment, you can just run <literal>nix-env -iA
nixpkgs.myPackages</literal>. If you want to load the packages to be built
from a working copy of <literal>nixpkgs</literal> you just run
<literal>nix-env -f. -iA myPackages</literal>. To explore what's been
installed, just look through <filename>~/.nix-profile/</filename>. You can
see that a lot of stuff has been installed. Some of this stuff is useful
some of it isn't. Let's tell Nixpkgs to only link the stuff that we want:
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; {
myPackages = pkgs.buildEnv {
@ -336,31 +349,30 @@ set of packages.
}
</screen>
<para>
<literal>pathsToLink</literal> tells Nixpkgs to only link the paths listed
which gets rid of the extra stuff in the profile.
<filename>/bin</filename> and <filename>/share</filename> are good
defaults for a user environment, getting rid of the clutter. If you are
running on Nix on MacOS, you may want to add another path as well,
<filename>/Applications</filename>, that makes GUI apps available.
</para>
<para>
<literal>pathsToLink</literal> tells Nixpkgs to only link the paths listed
which gets rid of the extra stuff in the profile. <filename>/bin</filename>
and <filename>/share</filename> are good defaults for a user environment,
getting rid of the clutter. If you are running on Nix on MacOS, you may
want to add another path as well, <filename>/Applications</filename>, that
makes GUI apps available.
</para>
</section>
<section xml:id="sec-getting-documentation">
<title>Getting documentation</title>
<title>Getting documentation</title>
<para>
After building that new environment, look through
<filename>~/.nix-profile</filename> to make sure everything is there that
we wanted. Discerning readers will note that some files are missing. Look
inside <filename>~/.nix-profile/share/man/man1/</filename> to verify this.
There are no man pages for any of the Nix tools! This is because some
packages like Nix have multiple outputs for things like documentation (see
section 4). Let's make Nix install those as well.
</para>
<para>
After building that new environment, look through
<filename>~/.nix-profile</filename> to make sure everything is there that
we wanted. Discerning readers will note that some files are missing. Look
inside <filename>~/.nix-profile/share/man/man1/</filename> to verify this.
There are no man pages for any of the Nix tools! This is because some
packages like Nix have multiple outputs for things like documentation (see
section 4). Let's make Nix install those as well.
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; {
myPackages = pkgs.buildEnv {
@ -373,14 +385,13 @@ set of packages.
}
</screen>
<para>
This provides us with some useful documentation for using our packages.
However, if we actually want those manpages to be detected by man, we need
to set up our environment. This can also be managed within Nix
expressions.
</para>
<para>
This provides us with some useful documentation for using our packages.
However, if we actually want those manpages to be detected by man, we need
to set up our environment. This can also be managed within Nix expressions.
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; rec {
myProfile = writeText "my-profile" ''
@ -412,13 +423,13 @@ cp ${myProfile} $out/etc/profile.d/my-profile.sh
}
</screen>
<para>
For this to work fully, you must also have this script sourced when you
are logged in. Try adding something like this to your
<filename>~/.profile</filename> file:
</para>
<para>
For this to work fully, you must also have this script sourced when you are
logged in. Try adding something like this to your
<filename>~/.profile</filename> file:
</para>
<screen>
<screen>
#!/bin/sh
if [ -d $HOME/.nix-profile/etc/profile.d ]; then
for i in $HOME/.nix-profile/etc/profile.d/*.sh; do
@ -429,23 +440,22 @@ if [ -d $HOME/.nix-profile/etc/profile.d ]; then
fi
</screen>
<para>
Now just run <literal>source $HOME/.profile</literal> and you can starting
loading man pages from your environent.
</para>
<para>
Now just run <literal>source $HOME/.profile</literal> and you can starting
loading man pages from your environent.
</para>
</section>
<section xml:id="sec-gnu-info-setup">
<title>GNU info setup</title>
<title>GNU info setup</title>
<para>
Configuring GNU info is a little bit trickier than man pages. To work
correctly, info needs a database to be generated. This can be done with
some small modifications to our environment scripts.
</para>
<para>
Configuring GNU info is a little bit trickier than man pages. To work
correctly, info needs a database to be generated. This can be done with
some small modifications to our environment scripts.
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; rec {
myProfile = writeText "my-profile" ''
@ -487,16 +497,13 @@ cp ${myProfile} $out/etc/profile.d/my-profile.sh
}
</screen>
<para>
<literal>postBuild</literal> tells Nixpkgs to run a command after building
the environment. In this case, <literal>install-info</literal> adds the
installed info pages to <literal>dir</literal> which is GNU info's default
root node. Note that <literal>texinfoInteractive</literal> is added to the
environment to give the <literal>install-info</literal> command.
</para>
<para>
<literal>postBuild</literal> tells Nixpkgs to run a command after building
the environment. In this case, <literal>install-info</literal> adds the
installed info pages to <literal>dir</literal> which is GNU info's default
root node. Note that <literal>texinfoInteractive</literal> is added to the
environment to give the <literal>install-info</literal> command.
</para>
</section>
</section>
</section>
</chapter>

38
doc/contributing.xml
View File

@ -1,35 +1,35 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-contributing">
<title>Contributing to this documentation</title>
<para>The DocBook sources of the Nixpkgs manual are in the <filename
<title>Contributing to this documentation</title>
<para>
The DocBook sources of the Nixpkgs manual are in the
<filename
xlink:href="https://github.com/NixOS/nixpkgs/tree/master/doc">doc</filename>
subdirectory of the Nixpkgs repository.</para>
<para>You can quickly check your edits with <command>make</command>:</para>
subdirectory of the Nixpkgs repository.
</para>
<para>
You can quickly check your edits with <command>make</command>:
</para>
<screen>
$ cd /path/to/nixpkgs/doc
$ nix-shell
[nix-shell]$ make
</screen>
<para>If you experience problems, run <command>make debug</command>
to help understand the docbook errors.</para>
<para>After making modifications to the manual, it's important to
build it before committing. You can do that as follows:
<para>
If you experience problems, run <command>make debug</command> to help
understand the docbook errors.
</para>
<para>
After making modifications to the manual, it's important to build it before
committing. You can do that as follows:
<screen>
$ cd /path/to/nixpkgs/doc
$ nix-shell
[nix-shell]$ make clean
[nix-shell]$ nix-build .
</screen>
If the build succeeds, the manual will be in
<filename>./result/share/doc/nixpkgs/manual.html</filename>.</para>
If the build succeeds, the manual will be in
<filename>./result/share/doc/nixpkgs/manual.html</filename>.
</para>
</chapter>

689
doc/cross-compilation.xml
View File

@ -1,308 +1,469 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-cross">
<title>Cross-compilation</title>
<section xml:id="sec-cross-intro">
<title>Cross-compilation</title>
<section xml:id="sec-cross-intro">
<title>Introduction</title>
<para>
"Cross-compilation" means compiling a program on one machine for another type of machine.
For example, a typical use of cross compilation is to compile programs for embedded devices.
These devices often don't have the computing power and memory to compile their own programs.
One might think that cross-compilation is a fairly niche concern, but there are advantages to being rigorous about distinguishing build-time vs run-time environments even when one is developing and deploying on the same machine.
Nixpkgs is increasingly adopting the opinion that packages should be written with cross-compilation in mind, and nixpkgs should evaluate in a similar way (by minimizing cross-compilation-specific special cases) whether or not one is cross-compiling.
"Cross-compilation" means compiling a program on one machine for another
type of machine. For example, a typical use of cross compilation is to
compile programs for embedded devices. These devices often don't have the
computing power and memory to compile their own programs. One might think
that cross-compilation is a fairly niche concern, but there are advantages
to being rigorous about distinguishing build-time vs run-time environments
even when one is developing and deploying on the same machine. Nixpkgs is
increasingly adopting the opinion that packages should be written with
cross-compilation in mind, and nixpkgs should evaluate in a similar way (by
minimizing cross-compilation-specific special cases) whether or not one is
cross-compiling.
</para>
<para>
This chapter will be organized in three parts.
First, it will describe the basics of how to package software in a way that supports cross-compilation.
Second, it will describe how to use Nixpkgs when cross-compiling.
Third, it will describe the internal infrastructure supporting cross-compilation.
This chapter will be organized in three parts. First, it will describe the
basics of how to package software in a way that supports cross-compilation.
Second, it will describe how to use Nixpkgs when cross-compiling. Third, it
will describe the internal infrastructure supporting cross-compilation.
</para>
</section>
</section>
<!--============================================================-->
<section xml:id="sec-cross-packaging">
<section xml:id="sec-cross-packaging">
<title>Packaging in a cross-friendly manner</title>
<section>
<title>Platform parameters</title>
<para>
Nixpkgs follows the <link xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Configure-Terms.html">common historical convention of GNU autoconf</link> of distinguishing between 3 types of platform: <wordasword>build</wordasword>, <wordasword>host</wordasword>, and <wordasword>target</wordasword>.
<title>Platform parameters</title>
In summary, <wordasword>build</wordasword> is the platform on which a package is being built, <wordasword>host</wordasword> is the platform on which it is to run. The third attribute, <wordasword>target</wordasword>, is relevant only for certain specific compilers and build tools.
</para>
<para>
Nixpkgs follows the
<link xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Configure-Terms.html">common
historical convention of GNU autoconf</link> of distinguishing between 3
types of platform: <wordasword>build</wordasword>,
<wordasword>host</wordasword>, and <wordasword>target</wordasword>. In
summary, <wordasword>build</wordasword> is the platform on which a package
is being built, <wordasword>host</wordasword> is the platform on which it
is to run. The third attribute, <wordasword>target</wordasword>, is
relevant only for certain specific compilers and build tools.
</para>
<para>
In Nixpkgs, these three platforms are defined as attribute sets under the names <literal>buildPlatform</literal>, <literal>hostPlatform</literal>, and <literal>targetPlatform</literal>.
All three are always defined as attributes in the standard environment, and at the top level. That means one can get at them just like a dependency in a function that is imported with <literal>callPackage</literal>:
<programlisting>{ stdenv, buildPlatform, hostPlatform, fooDep, barDep, .. }: ...buildPlatform...</programlisting>, or just off <varname>stdenv</varname>:
<programlisting>{ stdenv, fooDep, barDep, .. }: ...stdenv.buildPlatform...</programlisting>.
</para>
<variablelist>
<varlistentry>
<term><varname>buildPlatform</varname></term>
<listitem><para>
The "build platform" is the platform on which a package is built.
Once someone has a built package, or pre-built binary package, the build platform should not matter and be safe to ignore.
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>hostPlatform</varname></term>
<listitem><para>
The "host platform" is the platform on which a package will be run.
This is the simplest platform to understand, but also the one with the worst name.
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>targetPlatform</varname></term>
<listitem>
<para>
The "target platform" attribute is, unlike the other two attributes, not actually fundamental to the process of building software.
Instead, it is only relevant for compatibility with building certain specific compilers and build tools.
It can be safely ignored for all other packages.
</para>
<para>
The build process of certain compilers is written in such a way that the compiler resulting from a single build can itself only produce binaries for a single platform.
The task specifying this single "target platform" is thus pushed to build time of the compiler.
The root cause of this mistake is often that the compiler (which will be run on the host) and the the standard library/runtime (which will be run on the target) are built by a single build process.
</para>
<para>
There is no fundamental need to think about a single target ahead of time like this.
If the tool supports modular or pluggable backends, both the need to specify the target at build time and the constraint of having only a single target disappear.
An example of such a tool is LLVM.
</para>
<para>
Although the existence of a "target platfom" is arguably a historical mistake, it is a common one: examples of tools that suffer from it are GCC, Binutils, GHC and Autoconf.
Nixpkgs tries to avoid sharing in the mistake where possible.
Still, because the concept of a target platform is so ingrained, it is best to support it as is.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
The exact schema these fields follow is a bit ill-defined due to a long and convoluted evolution, but this is slowly being cleaned up.
You can see examples of ones used in practice in <literal>lib.systems.examples</literal>; note how they are not all very consistent.
For now, here are few fields can count on them containing:
</para>
<variablelist>
<varlistentry>
<term><varname>system</varname></term>
<listitem>
<para>
This is a two-component shorthand for the platform.
Examples of this would be "x86_64-darwin" and "i686-linux"; see <literal>lib.systems.doubles</literal> for more.
This format isn't very standard, but has built-in support in Nix, such as the <varname>builtins.currentSystem</varname> impure string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>config</varname></term>
<listitem>
<para>
This is a 3- or 4- component shorthand for the platform.
Examples of this would be "x86_64-unknown-linux-gnu" and "aarch64-apple-darwin14".
This is a standard format called the "LLVM target triple", as they are pioneered by LLVM and traditionally just used for the <varname>targetPlatform</varname>.
This format is strictly more informative than the "Nix host double", as the previous format could analogously be termed.
This needs a better name than <varname>config</varname>!
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>parsed</varname></term>
<listitem>
<para>
This is a nix representation of a parsed LLVM target triple with white-listed components.
This can be specified directly, or actually parsed from the <varname>config</varname>.
[Technically, only one need be specified and the others can be inferred, though the precision of inference may not be very good.]
See <literal>lib.systems.parse</literal> for the exact representation.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>libc</varname></term>
<listitem>
<para>
This is a string identifying the standard C library used.
Valid identifiers include "glibc" for GNU libc, "libSystem" for Darwin's Libsystem, and "uclibc" for µClibc.
It should probably be refactored to use the module system, like <varname>parse</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>is*</varname></term>
<listitem>
<para>
These predicates are defined in <literal>lib.systems.inspect</literal>, and slapped on every platform.
They are superior to the ones in <varname>stdenv</varname> as they force the user to be explicit about which platform they are inspecting.
Please use these instead of those.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>platform</varname></term>
<listitem>
<para>
This is, quite frankly, a dumping ground of ad-hoc settings (it's an attribute set).
See <literal>lib.systems.platforms</literal> for examples—there's hopefully one in there that will work verbatim for each platform that is working.
Please help us triage these flags and give them better homes!
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
In Nixpkgs, these three platforms are defined as attribute sets under the
names <literal>buildPlatform</literal>, <literal>hostPlatform</literal>,
and <literal>targetPlatform</literal>. All three are always defined as
attributes in the standard environment, and at the top level. That means
one can get at them just like a dependency in a function that is imported
with <literal>callPackage</literal>:
<programlisting>{ stdenv, buildPlatform, hostPlatform, fooDep, barDep, .. }: ...buildPlatform...</programlisting>
, or just off <varname>stdenv</varname>:
<programlisting>{ stdenv, fooDep, barDep, .. }: ...stdenv.buildPlatform...</programlisting>
.
</para>
<variablelist>
<varlistentry>
<term><varname>buildPlatform</varname>
</term>
<listitem>
<para>
The "build platform" is the platform on which a package is built. Once
someone has a built package, or pre-built binary package, the build
platform should not matter and be safe to ignore.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>hostPlatform</varname>
</term>
<listitem>
<para>
The "host platform" is the platform on which a package will be run. This
is the simplest platform to understand, but also the one with the worst
name.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>targetPlatform</varname>
</term>
<listitem>
<para>
The "target platform" attribute is, unlike the other two attributes, not
actually fundamental to the process of building software. Instead, it is
only relevant for compatibility with building certain specific compilers
and build tools. It can be safely ignored for all other packages.
</para>
<para>
The build process of certain compilers is written in such a way that the
compiler resulting from a single build can itself only produce binaries
for a single platform. The task specifying this single "target platform"
is thus pushed to build time of the compiler. The root cause of this
mistake is often that the compiler (which will be run on the host) and
the the standard library/runtime (which will be run on the target) are
built by a single build process.
</para>
<para>
There is no fundamental need to think about a single target ahead of
time like this. If the tool supports modular or pluggable backends, both
the need to specify the target at build time and the constraint of
having only a single target disappear. An example of such a tool is
LLVM.
</para>
<para>
Although the existence of a "target platfom" is arguably a historical
mistake, it is a common one: examples of tools that suffer from it are
GCC, Binutils, GHC and Autoconf. Nixpkgs tries to avoid sharing in the
mistake where possible. Still, because the concept of a target platform
is so ingrained, it is best to support it as is.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
The exact schema these fields follow is a bit ill-defined due to a long and
convoluted evolution, but this is slowly being cleaned up. You can see
examples of ones used in practice in
<literal>lib.systems.examples</literal>; note how they are not all very
consistent. For now, here are few fields can count on them containing:
</para>
<variablelist>
<varlistentry>
<term><varname>system</varname>
</term>
<listitem>
<para>
This is a two-component shorthand for the platform. Examples of this
would be "x86_64-darwin" and "i686-linux"; see
<literal>lib.systems.doubles</literal> for more. This format isn't very
standard, but has built-in support in Nix, such as the
<varname>builtins.currentSystem</varname> impure string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>config</varname>
</term>
<listitem>
<para>
This is a 3- or 4- component shorthand for the platform. Examples of
this would be "x86_64-unknown-linux-gnu" and "aarch64-apple-darwin14".
This is a standard format called the "LLVM target triple", as they are
pioneered by LLVM and traditionally just used for the
<varname>targetPlatform</varname>. This format is strictly more
informative than the "Nix host double", as the previous format could
analogously be termed. This needs a better name than
<varname>config</varname>!
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>parsed</varname>
</term>
<listitem>
<para>
This is a nix representation of a parsed LLVM target triple with
white-listed components. This can be specified directly, or actually
parsed from the <varname>config</varname>. [Technically, only one need
be specified and the others can be inferred, though the precision of
inference may not be very good.] See
<literal>lib.systems.parse</literal> for the exact representation.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>libc</varname>
</term>
<listitem>
<para>
This is a string identifying the standard C library used. Valid
identifiers include "glibc" for GNU libc, "libSystem" for Darwin's
Libsystem, and "uclibc" for µClibc. It should probably be refactored to
use the module system, like <varname>parse</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>is*</varname>
</term>
<listitem>
<para>
These predicates are defined in <literal>lib.systems.inspect</literal>,
and slapped on every platform. They are superior to the ones in
<varname>stdenv</varname> as they force the user to be explicit about
which platform they are inspecting. Please use these instead of those.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>platform</varname>
</term>
<listitem>
<para>
This is, quite frankly, a dumping ground of ad-hoc settings (it's an
attribute set). See <literal>lib.systems.platforms</literal> for
examples—there's hopefully one in there that will work verbatim for
each platform that is working. Please help us triage these flags and
give them better homes!
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>Specifying Dependencies</title>
<title>Specifying Dependencies</title>
<para>
In this section we explore the relationship between both runtime and
buildtime dependencies and the 3 Autoconf platforms.
</para>
<para>
A runtime dependency between 2 packages implies that between them both the
host and target platforms match. This is directly implied by the meaning of
"host platform" and "runtime dependency": The package dependency exists
while both packages are running on a single host platform.
</para>
<para>
A build time dependency, however, implies a shift in platforms between the
depending package and the depended-on package. The meaning of a build time
dependency is that to build the depending package we need to be able to run
the depended-on's package. The depending package's build platform is
therefore equal to the depended-on package's host platform. Analogously,
the depending package's host platform is equal to the depended-on package's
target platform.
</para>
<para>
In this manner, given the 3 platforms for one package, we can determine the
three platforms for all its transitive dependencies. This is the most
important guiding principle behind cross-compilation with Nixpkgs, and will
be called the <wordasword>sliding window principle</wordasword>.
</para>
<para>
Some examples will probably make this clearer. If a package is being built
with a <literal>(build, host, target)</literal> platform triple of
<literal>(foo, bar, bar)</literal>, then its build-time dependencies would
have a triple of <literal>(foo, foo, bar)</literal>, and <emphasis>those
packages'</emphasis> build-time dependencies would have triple of
<literal>(foo, foo, foo)</literal>. In other words, it should take two
"rounds" of following build-time dependency edges before one reaches a
fixed point where, by the sliding window principle, the platform triple no
longer changes. Indeed, this happens with cross compilation, where only
rounds of native dependencies starting with the second necessarily coincide
with native packages.
</para>
<note>
<para>
In this section we explore the relationship between both runtime and buildtime dependencies and the 3 Autoconf platforms.
The depending package's target platform is unconstrained by the sliding
window principle, which makes sense in that one can in principle build
cross compilers targeting arbitrary platforms.
</para>
</note>
<para>
How does this work in practice? Nixpkgs is now structured so that
build-time dependencies are taken from <varname>buildPackages</varname>,
whereas run-time dependencies are taken from the top level attribute set.
For example, <varname>buildPackages.gcc</varname> should be used at build
time, while <varname>gcc</varname> should be used at run time. Now, for
most of Nixpkgs's history, there was no <varname>buildPackages</varname>,
and most packages have not been refactored to use it explicitly. Instead,
one can use the six (<emphasis>gasp</emphasis>) attributes used for
specifying dependencies as documented in
<xref linkend="ssec-stdenv-dependencies"/>. We "splice" together the
run-time and build-time package sets with <varname>callPackage</varname>,
and then <varname>mkDerivation</varname> for each of four attributes pulls
the right derivation out. This splicing can be skipped when not cross
compiling as the package sets are the same, but is a bit slow for cross
compiling. Because of this, a best-of-both-worlds solution is in the works
with no splicing or explicit access of <varname>buildPackages</varname>
needed. For now, feel free to use either method.
</para>
<note>
<para>
A runtime dependency between 2 packages implies that between them both the host and target platforms match.
This is directly implied by the meaning of "host platform" and "runtime dependency":
The package dependency exists while both packages are running on a single host platform.
There is also a "backlink" <varname>targetPackages</varname>, yielding a
package set whose <varname>buildPackages</varname> is the current package
set. This is a hack, though, to accommodate compilers with lousy build
systems. Please do not use this unless you are absolutely sure you are
packaging such a compiler and there is no other way.
</para>
<para>
A build time dependency, however, implies a shift in platforms between the depending package and the depended-on package.
The meaning of a build time dependency is that to build the depending package we need to be able to run the depended-on's package.
The depending package's build platform is therefore equal to the depended-on package's host platform.
Analogously, the depending package's host platform is equal to the depended-on package's target platform.
</para>
<para>
In this manner, given the 3 platforms for one package, we can determine the three platforms for all its transitive dependencies.
This is the most important guiding principle behind cross-compilation with Nixpkgs, and will be called the <wordasword>sliding window principle</wordasword>.
</para>
<para>
Some examples will probably make this clearer.
If a package is being built with a <literal>(build, host, target)</literal> platform triple of <literal>(foo, bar, bar)</literal>, then its build-time dependencies would have a triple of <literal>(foo, foo, bar)</literal>, and <emphasis>those packages'</emphasis> build-time dependencies would have triple of <literal>(foo, foo, foo)</literal>.
In other words, it should take two "rounds" of following build-time dependency edges before one reaches a fixed point where, by the sliding window principle, the platform triple no longer changes.
Indeed, this happens with cross compilation, where only rounds of native dependencies starting with the second necessarily coincide with native packages.
</para>
<note><para>
The depending package's target platform is unconstrained by the sliding window principle, which makes sense in that one can in principle build cross compilers targeting arbitrary platforms.
</para></note>
<para>
How does this work in practice? Nixpkgs is now structured so that build-time dependencies are taken from <varname>buildPackages</varname>, whereas run-time dependencies are taken from the top level attribute set.
For example, <varname>buildPackages.gcc</varname> should be used at build time, while <varname>gcc</varname> should be used at run time.
Now, for most of Nixpkgs's history, there was no <varname>buildPackages</varname>, and most packages have not been refactored to use it explicitly.
Instead, one can use the six (<emphasis>gasp</emphasis>) attributes used for specifying dependencies as documented in <xref linkend="ssec-stdenv-dependencies"/>.
We "splice" together the run-time and build-time package sets with <varname>callPackage</varname>, and then <varname>mkDerivation</varname> for each of four attributes pulls the right derivation out.
This splicing can be skipped when not cross compiling as the package sets are the same, but is a bit slow for cross compiling.
Because of this, a best-of-both-worlds solution is in the works with no splicing or explicit access of <varname>buildPackages</varname> needed.
For now, feel free to use either method.
</para>
<note><para>
There is also a "backlink" <varname>targetPackages</varname>, yielding a package set whose <varname>buildPackages</varname> is the current package set.
This is a hack, though, to accommodate compilers with lousy build systems.
Please do not use this unless you are absolutely sure you are packaging such a compiler and there is no other way.
</para></note>
</note>
</section>
<section>
<title>Cross packagaing cookbook</title>
<para>
Some frequently problems when packaging for cross compilation are good to just spell and answer.
Ideally the information above is exhaustive, so this section cannot provide any new information,
but its ludicrous and cruel to expect everyone to spend effort working through the interaction of many features just to figure out the same answer to the same common problem.
Feel free to add to this list!
</para>
<qandaset>
<qandaentry>
<question><para>
What if my package's build system needs to build a C program to be run under the build environment?
</para></question>
<answer><para>
<programlisting>depsBuildBuild = [ buildPackages.stdenv.cc ];</programlisting>
Add it to your <function>mkDerivation</function> invocation.
</para></answer>
</qandaentry>
<qandaentry>
<question><para>
My package fails to find <command>ar</command>.
</para></question>
<answer><para>
Many packages assume that an unprefixed <command>ar</command> is available, but Nix doesn't provide one.
It only provides a prefixed one, just as it only does for all the other binutils programs.
It may be necessary to patch the package to fix the build system to use a prefixed `ar`.
</para></answer>
</qandaentry>
<qandaentry>
<question><para>
My package's testsuite needs to run host platform code.
</para></question>
<answer><para>
<programlisting>doCheck = stdenv.hostPlatform != stdenv.buildPlatfrom;</programlisting>
Add it to your <function>mkDerivation</function> invocation.
</para></answer>
</qandaentry>
</qandaset>
</section>
</section>
<title>Cross packagaing cookbook</title>
<para>
Some frequently problems when packaging for cross compilation are good to
just spell and answer. Ideally the information above is exhaustive, so this
section cannot provide any new information, but its ludicrous and cruel to
expect everyone to spend effort working through the interaction of many
features just to figure out the same answer to the same common problem.
Feel free to add to this list!
</para>
<qandaset>
<qandaentry>
<question>
<para>
What if my package's build system needs to build a C program to be run
under the build environment?
</para>
</question>
<answer>
<para>
<programlisting>depsBuildBuild = [ buildPackages.stdenv.cc ];</programlisting>
Add it to your <function>mkDerivation</function> invocation.
</para>
</answer>
</qandaentry>
<qandaentry>
<question>
<para>
My package fails to find <command>ar</command>.
</para>
</question>
<answer>
<para>
Many packages assume that an unprefixed <command>ar</command> is
available, but Nix doesn't provide one. It only provides a prefixed one,
just as it only does for all the other binutils programs. It may be
necessary to patch the package to fix the build system to use a prefixed
`ar`.
</para>
</answer>
</qandaentry>
<qandaentry>
<question>
<para>
My package's testsuite needs to run host platform code.
</para>
</question>
<answer>
<para>
<programlisting>doCheck = stdenv.hostPlatform != stdenv.buildPlatfrom;</programlisting>
Add it to your <function>mkDerivation</function> invocation.
</para>
</answer>
</qandaentry>
</qandaset>
</section>
</section>
<!--============================================================-->
<section xml:id="sec-cross-usage">
<section xml:id="sec-cross-usage">
<title>Cross-building packages</title>
<note><para>
More information needs to moved from the old wiki, especially <link xlink:href="https://nixos.org/wiki/CrossCompiling" />, for this section.
</para></note>
<note>
<para>
More information needs to moved from the old wiki, especially
<link xlink:href="https://nixos.org/wiki/CrossCompiling" />, for this
section.
</para>
</note>
<para>
Nixpkgs can be instantiated with <varname>localSystem</varname> alone, in which case there is no cross compiling and everything is built by and for that system,
or also with <varname>crossSystem</varname>, in which case packages run on the latter, but all building happens on the former.
Both parameters take the same schema as the 3 (build, host, and target) platforms defined in the previous section.
As mentioned above, <literal>lib.systems.examples</literal> has some platforms which are used as arguments for these parameters in practice.
You can use them programmatically, or on the command line: <programlisting>
Nixpkgs can be instantiated with <varname>localSystem</varname> alone, in
which case there is no cross compiling and everything is built by and for
that system, or also with <varname>crossSystem</varname>, in which case
packages run on the latter, but all building happens on the former. Both
parameters take the same schema as the 3 (build, host, and target) platforms
defined in the previous section. As mentioned above,
<literal>lib.systems.examples</literal> has some platforms which are used as
arguments for these parameters in practice. You can use them
programmatically, or on the command line:
<programlisting>
nix-build &lt;nixpkgs&gt; --arg crossSystem '(import &lt;nixpkgs/lib&gt;).systems.examples.fooBarBaz' -A whatever</programlisting>
</para>
<note>
<para>
Eventually we would like to make these platform examples an unnecessary convenience so that <programlisting>
<para>
Eventually we would like to make these platform examples an unnecessary
convenience so that
<programlisting>
nix-build &lt;nixpkgs&gt; --arg crossSystem.config '&lt;arch&gt;-&lt;os&gt;-&lt;vendor&gt;-&lt;abi&gt;' -A whatever</programlisting>
works in the vast majority of cases.
The problem today is dependencies on other sorts of configuration which aren't given proper defaults.
We rely on the examples to crudely to set those configuration parameters in some vaguely sane manner on the users behalf.
Issue <link xlink:href="https://github.com/NixOS/nixpkgs/issues/34274">#34274</link> tracks this inconvenience along with its root cause in crufty configuration options.
</para>
works in the vast majority of cases. The problem today is dependencies on
other sorts of configuration which aren't given proper defaults. We rely on
the examples to crudely to set those configuration parameters in some
vaguely sane manner on the users behalf. Issue
<link xlink:href="https://github.com/NixOS/nixpkgs/issues/34274">#34274</link>
tracks this inconvenience along with its root cause in crufty configuration
options.
</para>
</note>
<para>
While one is free to pass both parameters in full, there's a lot of logic to fill in missing fields.
As discussed in the previous section, only one of <varname>system</varname>, <varname>config</varname>, and <varname>parsed</varname> is needed to infer the other two.
Additionally, <varname>libc</varname> will be inferred from <varname>parse</varname>.
Finally, <literal>localSystem.system</literal> is also <emphasis>impurely</emphasis> inferred based on the platform evaluation occurs.
This means it is often not necessary to pass <varname>localSystem</varname> at all, as in the command-line example in the previous paragraph.
While one is free to pass both parameters in full, there's a lot of logic to
fill in missing fields. As discussed in the previous section, only one of
<varname>system</varname>, <varname>config</varname>, and
<varname>parsed</varname> is needed to infer the other two. Additionally,
<varname>libc</varname> will be inferred from <varname>parse</varname>.
Finally, <literal>localSystem.system</literal> is also
<emphasis>impurely</emphasis> inferred based on the platform evaluation
occurs. This means it is often not necessary to pass
<varname>localSystem</varname> at all, as in the command-line example in the
previous paragraph.
</para>
<note>
<para>
Many sources (manual, wiki, etc) probably mention passing <varname>system</varname>, <varname>platform</varname>, along with the optional <varname>crossSystem</varname> to nixpkgs:
<literal>import &lt;nixpkgs&gt; { system = ..; platform = ..; crossSystem = ..; }</literal>.
Passing those two instead of <varname>localSystem</varname> is still supported for compatibility, but is discouraged.
Indeed, much of the inference we do for these parameters is motivated by compatibility as much as convenience.
</para>
<para>
Many sources (manual, wiki, etc) probably mention passing
<varname>system</varname>, <varname>platform</varname>, along with the
optional <varname>crossSystem</varname> to nixpkgs: <literal>import
&lt;nixpkgs&gt; { system = ..; platform = ..; crossSystem = ..;
}</literal>. Passing those two instead of <varname>localSystem</varname> is
still supported for compatibility, but is discouraged. Indeed, much of the
inference we do for these parameters is motivated by compatibility as much
as convenience.
</para>
</note>
<para>
One would think that <varname>localSystem</varname> and <varname>crossSystem</varname> overlap horribly with the three <varname>*Platforms</varname> (<varname>buildPlatform</varname>, <varname>hostPlatform,</varname> and <varname>targetPlatform</varname>; see <varname>stage.nix</varname> or the manual).
Actually, those identifiers are purposefully not used here to draw a subtle but important distinction:
While the granularity of having 3 platforms is necessary to properly *build* packages, it is overkill for specifying the user's *intent* when making a build plan or package set.
A simple "build vs deploy" dichotomy is adequate: the sliding window principle described in the previous section shows how to interpolate between the these two "end points" to get the 3 platform triple for each bootstrapping stage.
That means for any package a given package set, even those not bound on the top level but only reachable via dependencies or <varname>buildPackages</varname>, the three platforms will be defined as one of <varname>localSystem</varname> or <varname>crossSystem</varname>, with the former replacing the latter as one traverses build-time dependencies.
A last simple difference then is <varname>crossSystem</varname> should be null when one doesn't want to cross-compile, while the <varname>*Platform</varname>s are always non-null.
<varname>localSystem</varname> is always non-null.
One would think that <varname>localSystem</varname> and
<varname>crossSystem</varname> overlap horribly with the three
<varname>*Platforms</varname> (<varname>buildPlatform</varname>,
<varname>hostPlatform,</varname> and <varname>targetPlatform</varname>; see
<varname>stage.nix</varname> or the manual). Actually, those identifiers are
purposefully not used here to draw a subtle but important distinction: While
the granularity of having 3 platforms is necessary to properly *build*
packages, it is overkill for specifying the user's *intent* when making a
build plan or package set. A simple "build vs deploy" dichotomy is adequate:
the sliding window principle described in the previous section shows how to
interpolate between the these two "end points" to get the 3 platform triple
for each bootstrapping stage. That means for any package a given package
set, even those not bound on the top level but only reachable via
dependencies or <varname>buildPackages</varname>, the three platforms will
be defined as one of <varname>localSystem</varname> or
<varname>crossSystem</varname>, with the former replacing the latter as one
traverses build-time dependencies. A last simple difference then is
<varname>crossSystem</varname> should be null when one doesn't want to
cross-compile, while the <varname>*Platform</varname>s are always non-null.
<varname>localSystem</varname> is always non-null.
</para>
</section>
</section>
<!--============================================================-->
<section xml:id="sec-cross-infra">
<section xml:id="sec-cross-infra">
<title>Cross-compilation infrastructure</title>
<para>To be written.</para>
<note><para>
If one explores nixpkgs, they will see derivations with names like <literal>gccCross</literal>.
Such <literal>*Cross</literal> derivations is a holdover from before we properly distinguished between the host and target platforms
—the derivation with "Cross" in the name covered the <literal>build = host != target</literal> case, while the other covered the <literal>host = target</literal>, with build platform the same or not based on whether one was using its <literal>.nativeDrv</literal> or <literal>.crossDrv</literal>.
This ugliness will disappear soon.
</para></note>
</section>
<para>
To be written.
</para>
<note>
<para>
If one explores nixpkgs, they will see derivations with names like
<literal>gccCross</literal>. Such <literal>*Cross</literal> derivations is
a holdover from before we properly distinguished between the host and
target platforms —the derivation with "Cross" in the name covered the
<literal>build = host != target</literal> case, while the other covered the
<literal>host = target</literal>, with build platform the same or not based
on whether one was using its <literal>.nativeDrv</literal> or
<literal>.crossDrv</literal>. This ugliness will disappear soon.
</para>
</note>
</section>
</chapter>

1096
doc/functions.xml
View File

File diff suppressed because it is too large Load Diff

520
doc/languages-frameworks/beam.xml
View File

@ -1,124 +1,137 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-beam">
<title>BEAM Languages (Erlang, Elixir &amp; LFE)</title>
<title>BEAM Languages (Erlang, Elixir &amp; LFE)</title>
<section xml:id="beam-introduction">
<title>Introduction</title>
<para>
In this document and related Nix expressions, we use the term,
<emphasis>BEAM</emphasis>, to describe the environment. BEAM is the name
of the Erlang Virtual Machine and, as far as we're concerned, from a
packaging perspective, all languages that run on the BEAM are
interchangeable. That which varies, like the build system, is transparent
to users of any given BEAM package, so we make no distinction.
</para>
</section>
<section xml:id="beam-structure">
<title>Structure</title>
<para>
All BEAM-related expressions are available via the top-level
<literal>beam</literal> attribute, which includes:
</para>
<itemizedlist>
<listitem>
<para>
<literal>interpreters</literal>: a set of compilers running on the
BEAM, including multiple Erlang/OTP versions
(<literal>beam.interpreters.erlangR19</literal>, etc), Elixir
(<literal>beam.interpreters.elixir</literal>) and LFE
(<literal>beam.interpreters.lfe</literal>).
</para>
</listitem>
<listitem>
<para>
<literal>packages</literal>: a set of package sets, each compiled with
a specific Erlang/OTP version, e.g.
<literal>beam.packages.erlangR19</literal>.
</para>
</listitem>
</itemizedlist>
<para>
The default Erlang compiler, defined by
<literal>beam.interpreters.erlang</literal>, is aliased as
<literal>erlang</literal>. The default BEAM package set is defined by
<literal>beam.packages.erlang</literal> and aliased at the top level as
<literal>beamPackages</literal>.
</para>
<para>
To create a package set built with a custom Erlang version, use the
lambda, <literal>beam.packagesWith</literal>, which accepts an Erlang/OTP
derivation and produces a package set similar to
<literal>beam.packages.erlang</literal>.
</para>
<para>
Many Erlang/OTP distributions available in
<literal>beam.interpreters</literal> have versions with ODBC and/or Java
enabled. For example, there's
<literal>beam.interpreters.erlangR19_odbc_javac</literal>, which
corresponds to <literal>beam.interpreters.erlangR19</literal>.
</para>
<para xml:id="erlang-call-package">
We also provide the lambda,
<literal>beam.packages.erlang.callPackage</literal>, which simplifies
writing BEAM package definitions by injecting all packages from
<literal>beam.packages.erlang</literal> into the top-level context.
</para>
</section>
<section xml:id="build-tools">
<title>Build Tools</title>
<section xml:id="build-tools-rebar3">
<title>Rebar3</title>
<para>
By default, Rebar3 wants to manage its own dependencies. This is perfectly
acceptable in the normal, non-Nix setup, but in the Nix world, it is not.
To rectify this, we provide two versions of Rebar3:
<itemizedlist>
<listitem>
<para>
<literal>rebar3</literal>: patched to remove the ability to download
anything. When not running it via <literal>nix-shell</literal> or
<literal>nix-build</literal>, it's probably not going to work as
desired.
</para>
</listitem>
<listitem>
<para>
<literal>rebar3-open</literal>: the normal, unmodified Rebar3. It
should work exactly as would any other version of Rebar3. Any Erlang
package should rely on <literal>rebar3</literal> instead. See <xref
linkend="rebar3-packages"/>.
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section xml:id="build-tools-other">
<title>Mix &amp; Erlang.mk</title>
<para>
Both Mix and Erlang.mk work exactly as expected. There is a bootstrap
process that needs to be run for both, however, which is supported by the
<literal>buildMix</literal> and <literal>buildErlangMk</literal>
derivations, respectively.
</para>
</section>
</section>
<section xml:id="beam-introduction">
<title>Introduction</title>
<section xml:id="how-to-install-beam-packages">
<title>How to Install BEAM Packages</title>
<para>
BEAM packages are not registered at the top level, simply because they are
not relevant to the vast majority of Nix users. They are installable using
the <literal>beam.packages.erlang</literal> attribute set (aliased as
<literal>beamPackages</literal>), which points to packages built by the
default Erlang/OTP version in Nixpkgs, as defined by
<literal>beam.interpreters.erlang</literal>.
In this document and related Nix expressions, we use the term,
<emphasis>BEAM</emphasis>, to describe the environment. BEAM is the name of
the Erlang Virtual Machine and, as far as we're concerned, from a packaging
perspective, all languages that run on the BEAM are interchangeable. That
which varies, like the build system, is transparent to users of any given
BEAM package, so we make no distinction.
</para>
</section>
To list the available packages in
<literal>beamPackages</literal>, use the following command:
<section xml:id="beam-structure">
<title>Structure</title>
<para>
All BEAM-related expressions are available via the top-level
<literal>beam</literal> attribute, which includes:
</para>
<programlisting>
<itemizedlist>
<listitem>
<para>
<literal>interpreters</literal>: a set of compilers running on the BEAM,
including multiple Erlang/OTP versions
(<literal>beam.interpreters.erlangR19</literal>, etc), Elixir
(<literal>beam.interpreters.elixir</literal>) and LFE
(<literal>beam.interpreters.lfe</literal>).
</para>
</listitem>
<listitem>
<para>
<literal>packages</literal>: a set of package sets, each compiled with a
specific Erlang/OTP version, e.g.
<literal>beam.packages.erlangR19</literal>.
</para>
</listitem>
</itemizedlist>
<para>
The default Erlang compiler, defined by
<literal>beam.interpreters.erlang</literal>, is aliased as
<literal>erlang</literal>. The default BEAM package set is defined by
<literal>beam.packages.erlang</literal> and aliased at the top level as
<literal>beamPackages</literal>.
</para>
<para>
To create a package set built with a custom Erlang version, use the lambda,
<literal>beam.packagesWith</literal>, which accepts an Erlang/OTP derivation
and produces a package set similar to
<literal>beam.packages.erlang</literal>.
</para>
<para>
Many Erlang/OTP distributions available in
<literal>beam.interpreters</literal> have versions with ODBC and/or Java
enabled. For example, there's
<literal>beam.interpreters.erlangR19_odbc_javac</literal>, which corresponds
to <literal>beam.interpreters.erlangR19</literal>.
</para>
<para xml:id="erlang-call-package">
We also provide the lambda,
<literal>beam.packages.erlang.callPackage</literal>, which simplifies
writing BEAM package definitions by injecting all packages from
<literal>beam.packages.erlang</literal> into the top-level context.
</para>
</section>
<section xml:id="build-tools">
<title>Build Tools</title>
<section xml:id="build-tools-rebar3">
<title>Rebar3</title>
<para>
By default, Rebar3 wants to manage its own dependencies. This is perfectly
acceptable in the normal, non-Nix setup, but in the Nix world, it is not.
To rectify this, we provide two versions of Rebar3:
<itemizedlist>
<listitem>
<para>
<literal>rebar3</literal>: patched to remove the ability to download
anything. When not running it via <literal>nix-shell</literal> or
<literal>nix-build</literal>, it's probably not going to work as
desired.
</para>
</listitem>
<listitem>
<para>
<literal>rebar3-open</literal>: the normal, unmodified Rebar3. It should
work exactly as would any other version of Rebar3. Any Erlang package
should rely on <literal>rebar3</literal> instead. See
<xref
linkend="rebar3-packages"/>.
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section xml:id="build-tools-other">
<title>Mix &amp; Erlang.mk</title>
<para>
Both Mix and Erlang.mk work exactly as expected. There is a bootstrap
process that needs to be run for both, however, which is supported by the
<literal>buildMix</literal> and <literal>buildErlangMk</literal>
derivations, respectively.
</para>
</section>
</section>
<section xml:id="how-to-install-beam-packages">
<title>How to Install BEAM Packages</title>
<para>
BEAM packages are not registered at the top level, simply because they are
not relevant to the vast majority of Nix users. They are installable using
the <literal>beam.packages.erlang</literal> attribute set (aliased as
<literal>beamPackages</literal>), which points to packages built by the
default Erlang/OTP version in Nixpkgs, as defined by
<literal>beam.interpreters.erlang</literal>. To list the available packages
in <literal>beamPackages</literal>, use the following command:
</para>
<programlisting>
$ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -qaP -A beamPackages
beamPackages.esqlite esqlite-0.2.1
beamPackages.goldrush goldrush-0.1.7
@ -128,34 +141,43 @@ beamPackages.lager lager-3.0.2
beamPackages.meck meck-0.8.3
beamPackages.rebar3-pc pc-1.1.0
</programlisting>
<para>
To install any of those packages into your profile, refer to them by their
attribute path (first column):
To install any of those packages into your profile, refer to them by their
attribute path (first column):
</para>
<programlisting>
<programlisting>
$ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
</programlisting>
<para>
The attribute path of any BEAM package corresponds to the name of that
particular package in <link xlink:href="https://hex.pm">Hex</link> or its
OTP Application/Release name.
The attribute path of any BEAM package corresponds to the name of that
particular package in <link xlink:href="https://hex.pm">Hex</link> or its
OTP Application/Release name.
</para>
</section>
<section xml:id="packaging-beam-applications">
</section>
<section xml:id="packaging-beam-applications">
<title>Packaging BEAM Applications</title>
<section xml:id="packaging-erlang-applications">
<title>Erlang Applications</title>
<section xml:id="rebar3-packages">
<title>Rebar3 Packages</title>
<para>
The Nix function, <literal>buildRebar3</literal>, defined in
<literal>beam.packages.erlang.buildRebar3</literal> and aliased at the
top level, can be used to build a derivation that understands how to
build a Rebar3 project. For example, we can build <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link> as
follows:
</para>
<programlisting>
<title>Erlang Applications</title>
<section xml:id="rebar3-packages">
<title>Rebar3 Packages</title>
<para>
The Nix function, <literal>buildRebar3</literal>, defined in
<literal>beam.packages.erlang.buildRebar3</literal> and aliased at the top
level, can be used to build a derivation that understands how to build a
Rebar3 project. For example, we can build
<link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>
as follows:
</para>
<programlisting>
{ stdenv, fetchFromGitHub, buildRebar3, ibrowse, jsx, erlware_commons }:
buildRebar3 rec {
@ -172,33 +194,40 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
beamDeps = [ ibrowse jsx erlware_commons ];
}
</programlisting>
<para>
Such derivations are callable with
<literal>beam.packages.erlang.callPackage</literal> (see <xref
linkend="erlang-call-package"/>). To call this package using the normal
<literal>callPackage</literal>, refer to dependency packages via
<literal>beamPackages</literal>, e.g.
<literal>beamPackages.ibrowse</literal>.
</para>
<para>
Notably, <literal>buildRebar3</literal> includes
<literal>beamDeps</literal>, while
<literal>stdenv.mkDerivation</literal> does not. BEAM dependencies added
there will be correctly handled by the system.
</para>
<para>
If a package needs to compile native code via Rebar3's port compilation
mechanism, add <literal>compilePort = true;</literal> to the derivation.
</para>
</section>
<section xml:id="erlang-mk-packages">
<title>Erlang.mk Packages</title>
<para>
Erlang.mk functions similarly to Rebar3, except we use
<literal>buildErlangMk</literal> instead of
<literal>buildRebar3</literal>.
</para>
<programlisting>
<para>
Such derivations are callable with
<literal>beam.packages.erlang.callPackage</literal> (see
<xref
linkend="erlang-call-package"/>). To call this package using
the normal <literal>callPackage</literal>, refer to dependency packages
via <literal>beamPackages</literal>, e.g.
<literal>beamPackages.ibrowse</literal>.
</para>
<para>
Notably, <literal>buildRebar3</literal> includes
<literal>beamDeps</literal>, while <literal>stdenv.mkDerivation</literal>
does not. BEAM dependencies added there will be correctly handled by the
system.
</para>
<para>
If a package needs to compile native code via Rebar3's port compilation
mechanism, add <literal>compilePort = true;</literal> to the derivation.
</para>
</section>
<section xml:id="erlang-mk-packages">
<title>Erlang.mk Packages</title>
<para>
Erlang.mk functions similarly to Rebar3, except we use
<literal>buildErlangMk</literal> instead of
<literal>buildRebar3</literal>.
</para>
<programlisting>
{ buildErlangMk, fetchHex, cowlib, ranch }:
buildErlangMk {
@ -222,14 +251,17 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
};
}
</programlisting>
</section>
<section xml:id="mix-packages">
<title>Mix Packages</title>
<para>
Mix functions similarly to Rebar3, except we use
<literal>buildMix</literal> instead of <literal>buildRebar3</literal>.
</para>
<programlisting>
</section>
<section xml:id="mix-packages">
<title>Mix Packages</title>
<para>
Mix functions similarly to Rebar3, except we use
<literal>buildMix</literal> instead of <literal>buildRebar3</literal>.
</para>
<programlisting>
{ buildMix, fetchHex, plug, absinthe }:
buildMix {
@ -253,10 +285,12 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
};
}
</programlisting>
<para>
Alternatively, we can use <literal>buildHex</literal> as a shortcut:
</para>
<programlisting>
<para>
Alternatively, we can use <literal>buildHex</literal> as a shortcut:
</para>
<programlisting>
{ buildHex, buildMix, plug, absinthe }:
buildHex {
@ -278,21 +312,25 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
};
}
</programlisting>
</section>
</section>
</section>
</section>
<section xml:id="how-to-develop">
</section>
<section xml:id="how-to-develop">
<title>How to Develop</title>
<section xml:id="accessing-an-environment">
<title>Accessing an Environment</title>
<para>
Often, we simply want to access a valid environment that contains a
specific package and its dependencies. We can accomplish that with the
<literal>env</literal> attribute of a derivation. For example, let's say
we want to access an Erlang REPL with <literal>ibrowse</literal> loaded
up. We could do the following:
</para>
<programlisting>
<title>Accessing an Environment</title>
<para>
Often, we simply want to access a valid environment that contains a
specific package and its dependencies. We can accomplish that with the
<literal>env</literal> attribute of a derivation. For example, let's say we
want to access an Erlang REPL with <literal>ibrowse</literal> loaded up. We
could do the following:
</para>
<programlisting>
$ nix-shell -A beamPackages.ibrowse.env --run "erl"
Erlang/OTP 18 [erts-7.0] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]
@ -333,22 +371,25 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
ok
2>
</programlisting>
<para>
Notice the <literal>-A beamPackages.ibrowse.env</literal>. That is the key
to this functionality.
</para>
<para>
Notice the <literal>-A beamPackages.ibrowse.env</literal>. That is the key
to this functionality.
</para>
</section>
<section xml:id="creating-a-shell">
<title>Creating a Shell</title>
<para>
Getting access to an environment often isn't enough to do real
development. Usually, we need to create a <literal>shell.nix</literal>
file and do our development inside of the environment specified therein.
This file looks a lot like the packaging described above, except that
<literal>src</literal> points to the project root and we call the package
directly.
</para>
<programlisting>
<title>Creating a Shell</title>
<para>
Getting access to an environment often isn't enough to do real development.
Usually, we need to create a <literal>shell.nix</literal> file and do our
development inside of the environment specified therein. This file looks a
lot like the packaging described above, except that <literal>src</literal>
points to the project root and we call the package directly.
</para>
<programlisting>
{ pkgs ? import &quot;&lt;nixpkgs&quot;&gt; {} }:
with pkgs;
@ -368,13 +409,16 @@ in
drv
</programlisting>
<section xml:id="building-in-a-shell">
<section xml:id="building-in-a-shell">
<title>Building in a Shell (for Mix Projects)</title>
<para>
We can leverage the support of the derivation, irrespective of the build
derivation, by calling the commands themselves.
We can leverage the support of the derivation, irrespective of the build
derivation, by calling the commands themselves.
</para>
<programlisting>
<programlisting>
# =============================================================================
# Variables
# =============================================================================
@ -431,44 +475,54 @@ analyze: build plt
$(NIX_SHELL) --run "mix dialyzer --no-compile"
</programlisting>
<para>
Using a <literal>shell.nix</literal> as described (see <xref
Using a <literal>shell.nix</literal> as described (see
<xref
linkend="creating-a-shell"/>) should just work. Aside from
<literal>test</literal>, <literal>plt</literal>, and
<literal>analyze</literal>, the Make targets work just fine for all of the
build derivations.
<literal>test</literal>, <literal>plt</literal>, and
<literal>analyze</literal>, the Make targets work just fine for all of the
build derivations.
</para>
</section>
</section>
</section>
</section>
<section xml:id="generating-packages-from-hex-with-hex2nix">
</section>
<section xml:id="generating-packages-from-hex-with-hex2nix">
<title>Generating Packages from Hex with <literal>hex2nix</literal></title>
<para>
Updating the <link xlink:href="https://hex.pm">Hex</link> package set
requires <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>. Given the
path to the Erlang modules (usually
<literal>pkgs/development/erlang-modules</literal>), it will dump a file
called <literal>hex-packages.nix</literal>, containing all the packages that
use a recognized build system in <link
xlink:href="https://hex.pm">Hex</link>. It can't be determined, however,
whether every package is buildable.
</para>
<para>
To make life easier for our users, try to build every <link
xlink:href="https://hex.pm">Hex</link> package and remove those that fail.
To do that, simply run the following command in the root of your
<literal>nixpkgs</literal> repository:
</para>
<programlisting>
Updating the <link xlink:href="https://hex.pm">Hex</link> package set
requires
<link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>.
Given the path to the Erlang modules (usually
<literal>pkgs/development/erlang-modules</literal>), it will dump a file
called <literal>hex-packages.nix</literal>, containing all the packages that
use a recognized build system in
<link
xlink:href="https://hex.pm">Hex</link>. It can't be determined,
however, whether every package is buildable.
</para>
<para>
To make life easier for our users, try to build every
<link
xlink:href="https://hex.pm">Hex</link> package and remove those
that fail. To do that, simply run the following command in the root of your
<literal>nixpkgs</literal> repository:
</para>
<programlisting>
$ nix-build -A beamPackages
</programlisting>
<para>
That will attempt to build every package in
<literal>beamPackages</literal>. Then manually remove those that fail.
Hopefully, someone will improve <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link> in the
future to automate the process.
</para>
</section>
<para>
That will attempt to build every package in <literal>beamPackages</literal>.
Then manually remove those that fail. Hopefully, someone will improve
<link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>
in the future to automate the process.
</para>
</section>
</section>

279
doc/languages-frameworks/bower.xml
View File

@ -1,40 +1,37 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-bower">
<title>Bower</title>
<title>Bower</title>
<para>
<link xlink:href="http://bower.io">Bower</link> is a package manager for web
site front-end components. Bower packages (comprising of build artefacts and
sometimes sources) are stored in <command>git</command> repositories,
typically on Github. The package registry is run by the Bower team with
package metadata coming from the <filename>bower.json</filename> file within
each package.
</para>
<para>
<link xlink:href="http://bower.io">Bower</link> is a package manager
for web site front-end components. Bower packages (comprising of
build artefacts and sometimes sources) are stored in
<command>git</command> repositories, typically on Github. The
package registry is run by the Bower team with package metadata
coming from the <filename>bower.json</filename> file within each
package.
</para>
<para>
The end result of running Bower is a <filename>bower_components</filename>
directory which can be included in the web app's build process.
</para>
<para>
The end result of running Bower is a
<filename>bower_components</filename> directory which can be included
in the web app's build process.
</para>
<para>
<para>
Bower can be run interactively, by installing
<varname>nodePackages.bower</varname>. More interestingly, the Bower
components can be declared in a Nix derivation, with the help of
<varname>nodePackages.bower2nix</varname>.
</para>
</para>
<section xml:id="ssec-bower2nix-usage">
<section xml:id="ssec-bower2nix-usage">
<title><command>bower2nix</command> usage</title>
<para>
Suppose you have a <filename>bower.json</filename> with the following contents:
<example xml:id="ex-bowerJson"><title><filename>bower.json</filename></title>
<para>
Suppose you have a <filename>bower.json</filename> with the following
contents:
<example xml:id="ex-bowerJson">
<title><filename>bower.json</filename></title>
<programlisting language="json">
<![CDATA[{
"name": "my-web-app",
@ -44,14 +41,12 @@
}
}]]>
</programlisting>
</example>
</para>
<para>
Running <command>bower2nix</command> will produce something like the
following output:
</example>
</para>
<para>
Running <command>bower2nix</command> will produce something like the
following output:
<programlisting language="nix">
<![CDATA[{ fetchbower, buildEnv }:
buildEnv { name = "bower-env"; ignoreCollisions = true; paths = [
@ -60,31 +55,31 @@ buildEnv { name = "bower-env"; ignoreCollisions = true; paths = [
(fetchbower "jquery" "2.2.2" "1.9.1 - 2" "10sp5h98sqwk90y4k6hbdviwqzvzwqf47r3r51pakch5ii2y7js1")
]; }]]>
</programlisting>
</para>
<para>
Using the <command>bower2nix</command> command line arguments, the
output can be redirected to a file. A name like
<filename>bower-packages.nix</filename> would be fine.
</para>
<para>
The resulting derivation is a union of all the downloaded Bower
packages (and their dependencies). To use it, they still need to be
linked together by Bower, which is where
<varname>buildBowerComponents</varname> is useful.
</para>
</section>
<section xml:id="ssec-build-bower-components"><title><varname>buildBowerComponents</varname> function</title>
</para>
<para>
The function is implemented in <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/bower-modules/generic/default.nix">
<filename>pkgs/development/bower-modules/generic/default.nix</filename></link>.
Example usage:
Using the <command>bower2nix</command> command line arguments, the output
can be redirected to a file. A name like
<filename>bower-packages.nix</filename> would be fine.
</para>
<example xml:id="ex-buildBowerComponents"><title>buildBowerComponents</title>
<para>
The resulting derivation is a union of all the downloaded Bower packages
(and their dependencies). To use it, they still need to be linked together
by Bower, which is where <varname>buildBowerComponents</varname> is useful.
</para>
</section>
<section xml:id="ssec-build-bower-components">
<title><varname>buildBowerComponents</varname> function</title>
<para>
The function is implemented in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/bower-modules/generic/default.nix">
<filename>pkgs/development/bower-modules/generic/default.nix</filename></link>.
Example usage:
<example xml:id="ex-buildBowerComponents">
<title>buildBowerComponents</title>
<programlisting language="nix">
bowerComponents = buildBowerComponents {
name = "my-web-app";
@ -92,42 +87,42 @@ bowerComponents = buildBowerComponents {
src = myWebApp; <co xml:id="ex-buildBowerComponents-2" />
};
</programlisting>
</example>
</example>
</para>
<para>
In <xref linkend="ex-buildBowerComponents" />, the following arguments
are of special significance to the function:
<para>
In <xref linkend="ex-buildBowerComponents" />, the following arguments are
of special significance to the function:
<calloutlist>
<callout arearefs="ex-buildBowerComponents-1">
<para>
<varname>generated</varname> specifies the file which was created by
<command>bower2nix</command>.
</para>
</callout>
<callout arearefs="ex-buildBowerComponents-2">
<para>
<varname>src</varname> is your project's sources. It needs to contain a
<filename>bower.json</filename> file.
</para>
</callout>
</calloutlist>
</para>
<calloutlist>
<callout arearefs="ex-buildBowerComponents-1">
<para>
<varname>generated</varname> specifies the file which was created by <command>bower2nix</command>.
</para>
</callout>
<para>
<varname>buildBowerComponents</varname> will run Bower to link together the
output of <command>bower2nix</command>, resulting in a
<filename>bower_components</filename> directory which can be used.
</para>
<callout arearefs="ex-buildBowerComponents-2">
<para>
<varname>src</varname> is your project's sources. It needs to
contain a <filename>bower.json</filename> file.
</para>
</callout>
</calloutlist>
</para>
<para>
Here is an example of a web frontend build process using
<command>gulp</command>. You might use <command>grunt</command>, or anything
else.
</para>
<para>
<varname>buildBowerComponents</varname> will run Bower to link
together the output of <command>bower2nix</command>, resulting in a
<filename>bower_components</filename> directory which can be used.
</para>
<para>
Here is an example of a web frontend build process using
<command>gulp</command>. You might use <command>grunt</command>, or
anything else.
</para>
<example xml:id="ex-bowerGulpFile"><title>Example build script (<filename>gulpfile.js</filename>)</title>
<example xml:id="ex-bowerGulpFile">
<title>Example build script (<filename>gulpfile.js</filename>)</title>
<programlisting language="javascript">
<![CDATA[var gulp = require('gulp');
@ -142,10 +137,10 @@ gulp.task('build', [], function () {
.pipe(gulp.dest("./gulpdist/"));
});]]>
</programlisting>
</example>
</example>
<example xml:id="ex-buildBowerComponentsDefaultNix">
<title>Full example — <filename>default.nix</filename></title>
<example xml:id="ex-buildBowerComponentsDefaultNix">
<title>Full example — <filename>default.nix</filename></title>
<programlisting language="nix">
{ myWebApp ? { outPath = ./.; name = "myWebApp"; }
, pkgs ? import &lt;nixpkgs&gt; {}
@ -172,73 +167,63 @@ pkgs.stdenv.mkDerivation {
installPhase = "mv gulpdist $out";
}
</programlisting>
</example>
</example>
<para>
A few notes about <xref linkend="ex-buildBowerComponentsDefaultNix" />:
<calloutlist>
<callout arearefs="ex-buildBowerComponentsDefault-1">
<para>
The result of <varname>buildBowerComponents</varname> is an
input to the frontend build.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-2">
<para>
Whether to symlink or copy the
<filename>bower_components</filename> directory depends on the
build tool in use. In this case a copy is used to avoid
<command>gulp</command> silliness with permissions.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-3">
<para>
<command>gulp</command> requires <varname>HOME</varname> to
refer to a writeable directory.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-4">
<para>
<para>
A few notes about <xref linkend="ex-buildBowerComponentsDefaultNix" />:
<calloutlist>
<callout arearefs="ex-buildBowerComponentsDefault-1">
<para>
The result of <varname>buildBowerComponents</varname> is an input to the
frontend build.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-2">
<para>
Whether to symlink or copy the <filename>bower_components</filename>
directory depends on the build tool in use. In this case a copy is used
to avoid <command>gulp</command> silliness with permissions.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-3">
<para>
<command>gulp</command> requires <varname>HOME</varname> to refer to a
writeable directory.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-4">
<para>
The actual build command. Other tools could be used.
</para>
</callout>
</calloutlist>
</para>
</section>
</para>
</callout>
</calloutlist>
</para>
</section>
<section xml:id="ssec-bower2nix-troubleshooting">
<section xml:id="ssec-bower2nix-troubleshooting">
<title>Troubleshooting</title>
<variablelist>
<varlistentry>
<term>
<literal>ENOCACHE</literal> errors from
<variablelist>
<varlistentry>
<term><literal>ENOCACHE</literal> errors from
<varname>buildBowerComponents</varname>
</term>
<listitem>
<para>
This means that Bower was looking for a package version which
doesn't exist in the generated
<filename>bower-packages.nix</filename>.
</para>
<para>
If <filename>bower.json</filename> has been updated, then run
<command>bower2nix</command> again.
</para>
<para>
It could also be a bug in <command>bower2nix</command> or
<command>fetchbower</command>. If possible, try reformulating
the version specification in <filename>bower.json</filename>.
</para>
<para>
This means that Bower was looking for a package version which doesn't
exist in the generated <filename>bower-packages.nix</filename>.
</para>
<para>
If <filename>bower.json</filename> has been updated, then run
<command>bower2nix</command> again.
</para>
<para>
It could also be a bug in <command>bower2nix</command> or
<command>fetchbower</command>. If possible, try reformulating the version
specification in <filename>bower.json</filename>.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
</varlistentry>
</variablelist>
</section>
</section>

60
doc/languages-frameworks/coq.xml
View File

@ -1,36 +1,38 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-coq">
<title>Coq</title>
<title>Coq</title>
<para>
Coq libraries should be installed in
<literal>$(out)/lib/coq/${coq.coq-version}/user-contrib/</literal>.
Such directories are automatically added to the
<literal>$COQPATH</literal> environment variable by the hook defined
in the Coq derivation.
</para>
<para>
Some libraries require OCaml and sometimes also Camlp5 or findlib.
The exact versions that were used to build Coq are saved in the
<literal>coq.ocaml</literal> and <literal>coq.camlp5</literal>
and <literal>coq.findlib</literal> attributes.
</para>
<para>
Coq libraries may be compatible with some specific versions of Coq only.
The <literal>compatibleCoqVersions</literal> attribute is used to
precisely select those versions of Coq that are compatible with this
derivation.
</para>
<para>
Here is a simple package example. It is a pure Coq library, thus it
depends on Coq. It builds on the Mathematical Components library, thus it
also takes <literal>mathcomp</literal> as <literal>buildInputs</literal>.
Its <literal>Makefile</literal> has been generated using
<literal>coq_makefile</literal> so we only have to
set the <literal>$COQLIB</literal> variable at install time.
</para>
<programlisting>
<para>
Coq libraries should be installed in
<literal>$(out)/lib/coq/${coq.coq-version}/user-contrib/</literal>. Such
directories are automatically added to the <literal>$COQPATH</literal>
environment variable by the hook defined in the Coq derivation.
</para>
<para>
Some libraries require OCaml and sometimes also Camlp5 or findlib. The exact
versions that were used to build Coq are saved in the
<literal>coq.ocaml</literal> and <literal>coq.camlp5</literal> and
<literal>coq.findlib</literal> attributes.
</para>
<para>
Coq libraries may be compatible with some specific versions of Coq only. The
<literal>compatibleCoqVersions</literal> attribute is used to precisely
select those versions of Coq that are compatible with this derivation.
</para>
<para>
Here is a simple package example. It is a pure Coq library, thus it depends
on Coq. It builds on the Mathematical Components library, thus it also takes
<literal>mathcomp</literal> as <literal>buildInputs</literal>. Its
<literal>Makefile</literal> has been generated using
<literal>coq_makefile</literal> so we only have to set the
<literal>$COQLIB</literal> variable at install time.
</para>
<programlisting>
{ stdenv, fetchFromGitHub, coq, mathcomp }:
stdenv.mkDerivation rec {

164
doc/languages-frameworks/go.xml
View File

@ -1,14 +1,14 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-go">
<title>Go</title>
<title>Go</title>
<para>
The function <varname>buildGoPackage</varname> builds standard Go programs.
</para>
<para>The function <varname>buildGoPackage</varname> builds
standard Go programs.
</para>
<example xml:id='ex-buildGoPackage'><title>buildGoPackage</title>
<example xml:id='ex-buildGoPackage'>
<title>buildGoPackage</title>
<programlisting>
deis = buildGoPackage rec {
name = "deis-${version}";
@ -29,55 +29,56 @@ deis = buildGoPackage rec {
buildFlags = "--tags release"; <co xml:id='ex-buildGoPackage-4' />
}
</programlisting>
</example>
</example>
<para><xref linkend='ex-buildGoPackage'/> is an example expression using buildGoPackage,
the following arguments are of special significance to the function:
<calloutlist>
<callout arearefs='ex-buildGoPackage-1'>
<para>
<xref linkend='ex-buildGoPackage'/> is an example expression using
buildGoPackage, the following arguments are of special significance to the
function:
<calloutlist>
<callout arearefs='ex-buildGoPackage-1'>
<para>
<varname>goPackagePath</varname> specifies the package's canonical Go import path.
<varname>goPackagePath</varname> specifies the package's canonical Go
import path.
</para>
</callout>
<callout arearefs='ex-buildGoPackage-2'>
</callout>
<callout arearefs='ex-buildGoPackage-2'>
<para>
<varname>subPackages</varname> limits the builder from building child packages that
have not been listed. If <varname>subPackages</varname> is not specified, all child
packages will be built.
<varname>subPackages</varname> limits the builder from building child
packages that have not been listed. If <varname>subPackages</varname> is
not specified, all child packages will be built.
</para>
<para>
In this example only <literal>github.com/deis/deis/client</literal> will be built.
In this example only <literal>github.com/deis/deis/client</literal> will
be built.
</para>
</callout>
<callout arearefs='ex-buildGoPackage-3'>
</callout>
<callout arearefs='ex-buildGoPackage-3'>
<para>
<varname>goDeps</varname> is where the Go dependencies of a Go program are listed
as a list of package source identified by Go import path.
It could be imported as a separate <varname>deps.nix</varname> file for
readability. The dependency data structure is described below.
<varname>goDeps</varname> is where the Go dependencies of a Go program are
listed as a list of package source identified by Go import path. It could
be imported as a separate <varname>deps.nix</varname> file for
readability. The dependency data structure is described below.
</para>
</callout>
<callout arearefs='ex-buildGoPackage-4'>
</callout>
<callout arearefs='ex-buildGoPackage-4'>
<para>
<varname>buildFlags</varname> is a list of flags passed to the go build command.
<varname>buildFlags</varname> is a list of flags passed to the go build
command.
</para>
</callout>
</callout>
</calloutlist>
</para>
</calloutlist>
<para>
The <varname>goDeps</varname> attribute can be imported from a separate
<varname>nix</varname> file that defines which Go libraries are needed and
should be included in <varname>GOPATH</varname> for
<varname>buildPhase</varname>.
</para>
</para>
<para>The <varname>goDeps</varname> attribute can be imported from a separate
<varname>nix</varname> file that defines which Go libraries are needed and should
be included in <varname>GOPATH</varname> for <varname>buildPhase</varname>.
</para>
<example xml:id='ex-goDeps'><title>deps.nix</title>
<example xml:id='ex-goDeps'>
<title>deps.nix</title>
<programlisting>
[ <co xml:id='ex-goDeps-1' />
{
@ -100,67 +101,60 @@ the following arguments are of special significance to the function:
}
]
</programlisting>
</example>
</example>
<para>
<calloutlist>
<callout arearefs='ex-goDeps-1'>
<para>
<calloutlist>
<callout arearefs='ex-goDeps-1'>
<para>
<varname>goDeps</varname> is a list of Go dependencies.
<varname>goDeps</varname> is a list of Go dependencies.
</para>
</callout>
<callout arearefs='ex-goDeps-2'>
</callout>
<callout arearefs='ex-goDeps-2'>
<para>
<varname>goPackagePath</varname> specifies Go package import path.
<varname>goPackagePath</varname> specifies Go package import path.
</para>
</callout>
<callout arearefs='ex-goDeps-3'>
</callout>
<callout arearefs='ex-goDeps-3'>
<para>
<varname>fetch type</varname> that needs to be used to get package source. If <varname>git</varname>
is used there should be <varname>url</varname>, <varname>rev</varname> and <varname>sha256</varname>
defined next to it.
<varname>fetch type</varname> that needs to be used to get package source.
If <varname>git</varname> is used there should be <varname>url</varname>,
<varname>rev</varname> and <varname>sha256</varname> defined next to it.
</para>
</callout>
</callout>
</calloutlist>
</para>
</calloutlist>
<para>
To extract dependency information from a Go package in automated way use
<link xlink:href="https://github.com/kamilchm/go2nix">go2nix</link>. It can
produce complete derivation and <varname>goDeps</varname> file for Go
programs.
</para>
</para>
<para>To extract dependency information from a Go package in automated way use <link xlink:href="https://github.com/kamilchm/go2nix">go2nix</link>.
It can produce complete derivation and <varname>goDeps</varname> file for Go programs.</para>
<para>
<varname>buildGoPackage</varname> produces <xref linkend='chap-multiple-output' xrefstyle="select: title" />
where <varname>bin</varname> includes program binaries. You can test build a Go binary as follows:
<screen>
<para>
<varname>buildGoPackage</varname> produces
<xref linkend='chap-multiple-output' xrefstyle="select: title" /> where
<varname>bin</varname> includes program binaries. You can test build a Go
binary as follows:
<screen>
$ nix-build -A deis.bin
</screen>
or build all outputs with:
<screen>
<screen>
$ nix-build -A deis.all
</screen>
<varname>bin</varname> output will be installed by default with
<varname>nix-env -i</varname> or <varname>systemPackages</varname>.
</para>
<varname>bin</varname> output will be installed by default with <varname>nix-env -i</varname>
or <varname>systemPackages</varname>.
</para>
<para>
You may use Go packages installed into the active Nix profiles by adding
the following to your ~/.bashrc:
<para>
You may use Go packages installed into the active Nix profiles by adding the
following to your ~/.bashrc:
<screen>
for p in $NIX_PROFILES; do
GOPATH="$p/share/go:$GOPATH"
done
</screen>
</para>
</para>
</section>

59
doc/languages-frameworks/index.xml
View File

@ -1,36 +1,31 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xml:id="chap-language-support">
<title>Support for specific programming languages and frameworks</title>
<para>The <link linkend="chap-stdenv">standard build
environment</link> makes it easy to build typical Autotools-based
packages with very little code. Any other kind of package can be
accomodated by overriding the appropriate phases of
<literal>stdenv</literal>. However, there are specialised functions
in Nixpkgs to easily build packages for other programming languages,
such as Perl or Haskell. These are described in this chapter.</para>
<xi:include href="beam.xml" />
<xi:include href="bower.xml" />
<xi:include href="coq.xml" />
<xi:include href="go.xml" />
<xi:include href="haskell.section.xml" />
<xi:include href="idris.section.xml" />
<xi:include href="java.xml" />
<xi:include href="lua.xml" />
<xi:include href="node.section.xml" />
<xi:include href="perl.xml" />
<xi:include href="python.section.xml" />
<xi:include href="qt.xml" />
<xi:include href="r.section.xml" />
<xi:include href="ruby.xml" />
<xi:include href="rust.section.xml" />
<xi:include href="texlive.xml" />
<xi:include href="vim.section.xml" />
<xi:include href="emscripten.section.xml" />
<title>Support for specific programming languages and frameworks</title>
<para>
The <link linkend="chap-stdenv">standard build environment</link> makes it
easy to build typical Autotools-based packages with very little code. Any
other kind of package can be accomodated by overriding the appropriate phases
of <literal>stdenv</literal>. However, there are specialised functions in
Nixpkgs to easily build packages for other programming languages, such as
Perl or Haskell. These are described in this chapter.
</para>
<xi:include href="beam.xml" />
<xi:include href="bower.xml" />
<xi:include href="coq.xml" />
<xi:include href="go.xml" />
<xi:include href="haskell.section.xml" />
<xi:include href="idris.section.xml" />
<xi:include href="java.xml" />
<xi:include href="lua.xml" />
<xi:include href="node.section.xml" />
<xi:include href="perl.xml" />
<xi:include href="python.section.xml" />
<xi:include href="qt.xml" />
<xi:include href="r.section.xml" />
<xi:include href="ruby.xml" />
<xi:include href="rust.section.xml" />
<xi:include href="texlive.xml" />
<xi:include href="vim.section.xml" />
<xi:include href="emscripten.section.xml" />
</chapter>

76
doc/languages-frameworks/java.xml
View File

@ -1,11 +1,10 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-java">
<title>Java</title>
<title>Java</title>
<para>Ant-based Java packages are typically built from source as follows:
<para>
Ant-based Java packages are typically built from source as follows:
<programlisting>
stdenv.mkDerivation {
name = "...";
@ -16,33 +15,33 @@ stdenv.mkDerivation {
buildPhase = "ant";
}
</programlisting>
Note that <varname>jdk</varname> is an alias for the OpenJDK.
</para>
Note that <varname>jdk</varname> is an alias for the OpenJDK.</para>
<para>JAR files that are intended to be used by other packages should
be installed in <filename>$out/share/java</filename>. The OpenJDK has
a stdenv setup hook that adds any JARs in the
<filename>share/java</filename> directories of the build inputs to the
<envar>CLASSPATH</envar> environment variable. For instance, if the
package <literal>libfoo</literal> installs a JAR named
<filename>foo.jar</filename> in its <filename>share/java</filename>
directory, and another package declares the attribute
<para>
JAR files that are intended to be used by other packages should be installed
in <filename>$out/share/java</filename>. The OpenJDK has a stdenv setup hook
that adds any JARs in the <filename>share/java</filename> directories of the
build inputs to the <envar>CLASSPATH</envar> environment variable. For
instance, if the package <literal>libfoo</literal> installs a JAR named
<filename>foo.jar</filename> in its <filename>share/java</filename>
directory, and another package declares the attribute
<programlisting>
buildInputs = [ jdk libfoo ];
</programlisting>
then <envar>CLASSPATH</envar> will be set to
<filename>/nix/store/...-libfoo/share/java/foo.jar</filename>.
</para>
then <envar>CLASSPATH</envar> will be set to
<filename>/nix/store/...-libfoo/share/java/foo.jar</filename>.</para>
<para>Private JARs
should be installed in a location like
<filename>$out/share/<replaceable>package-name</replaceable></filename>.</para>
<para>If your Java package provides a program, you need to generate a
wrapper script to run it using the OpenJRE. You can use
<literal>makeWrapper</literal> for this:
<para>
Private JARs should be installed in a location like
<filename>$out/share/<replaceable>package-name</replaceable></filename>.
</para>
<para>
If your Java package provides a program, you need to generate a wrapper
script to run it using the OpenJRE. You can use
<literal>makeWrapper</literal> for this:
<programlisting>
buildInputs = [ makeWrapper ];
@ -53,23 +52,20 @@ installPhase =
--add-flags "-cp $out/share/java/foo.jar org.foo.Main"
'';
</programlisting>
Note the use of <literal>jre</literal>, which is the part of the OpenJDK
package that contains the Java Runtime Environment. By using
<literal>${jre}/bin/java</literal> instead of
<literal>${jdk}/bin/java</literal>, you prevent your package from depending
on the JDK at runtime.
</para>
Note the use of <literal>jre</literal>, which is the part of the
OpenJDK package that contains the Java Runtime Environment. By using
<literal>${jre}/bin/java</literal> instead of
<literal>${jdk}/bin/java</literal>, you prevent your package from
depending on the JDK at runtime.</para>
<para>It is possible to use a different Java compiler than
<command>javac</command> from the OpenJDK. For instance, to use the
GNU Java Compiler:
<para>
It is possible to use a different Java compiler than <command>javac</command>
from the OpenJDK. For instance, to use the GNU Java Compiler:
<programlisting>
buildInputs = [ gcj ant ];
</programlisting>
Here, Ant will automatically use <command>gij</command> (the GNU Java
Runtime) instead of the OpenJRE.</para>
Here, Ant will automatically use <command>gij</command> (the GNU Java
Runtime) instead of the OpenJRE.
</para>
</section>

43
doc/languages-frameworks/lua.xml
View File

@ -1,24 +1,22 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-lua">
<title>Lua</title>
<title>Lua</title>
<para>
Lua packages are built by the <varname>buildLuaPackage</varname> function. This function is
implemented
in <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/lua-modules/generic/default.nix">
<para>
Lua packages are built by the <varname>buildLuaPackage</varname> function.
This function is implemented in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/lua-modules/generic/default.nix">
<filename>pkgs/development/lua-modules/generic/default.nix</filename></link>
and works similarly to <varname>buildPerlPackage</varname>. (See
<xref linkend="sec-language-perl"/> for details.)
</para>
</para>
<para>
Lua packages are defined
in <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/lua-packages.nix"><filename>pkgs/top-level/lua-packages.nix</filename></link>.
<para>
Lua packages are defined in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/lua-packages.nix"><filename>pkgs/top-level/lua-packages.nix</filename></link>.
Most of them are simple. For example:
<programlisting>
<programlisting>
fileSystem = buildLuaPackage {
name = "filesystem-1.6.2";
src = fetchurl {
@ -32,20 +30,19 @@ fileSystem = buildLuaPackage {
};
};
</programlisting>
</para>
</para>
<para>
<para>
Though, more complicated package should be placed in a seperate file in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/lua-modules"><filename>pkgs/development/lua-modules</filename></link>.
</para>
<para>
Lua packages accept additional parameter <varname>disabled</varname>, which defines
the condition of disabling package from luaPackages. For example, if package has
<varname>disabled</varname> assigned to <literal>lua.luaversion != "5.1"</literal>,
it will not be included in any luaPackages except lua51Packages, making it
only be built for lua 5.1.
</para>
</para>
<para>
Lua packages accept additional parameter <varname>disabled</varname>, which
defines the condition of disabling package from luaPackages. For example, if
package has <varname>disabled</varname> assigned to <literal>lua.luaversion
!= "5.1"</literal>, it will not be included in any luaPackages except
lua51Packages, making it only be built for lua 5.1.
</para>
</section>

219
doc/languages-frameworks/perl.xml
View File

@ -1,24 +1,27 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-perl">
<title>Perl</title>
<title>Perl</title>
<para>
Nixpkgs provides a function <varname>buildPerlPackage</varname>, a generic
package builder function for any Perl package that has a standard
<varname>Makefile.PL</varname>. It’s implemented in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/perl-modules/generic"><filename>pkgs/development/perl-modules/generic</filename></link>.
</para>
<para>Nixpkgs provides a function <varname>buildPerlPackage</varname>,
a generic package builder function for any Perl package that has a
standard <varname>Makefile.PL</varname>. It’s implemented in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/perl-modules/generic"><filename>pkgs/development/perl-modules/generic</filename></link>.</para>
<para>Perl packages from CPAN are defined in <link
<para>
Perl packages from CPAN are defined in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link>,
rather than <filename>pkgs/all-packages.nix</filename>. Most Perl
packages are so straight-forward to build that they are defined here
directly, rather than having a separate function for each package
called from <filename>perl-packages.nix</filename>. However, more
complicated packages should be put in a separate file, typically in
<filename>pkgs/development/perl-modules</filename>. Here is an
example of the former:
rather than <filename>pkgs/all-packages.nix</filename>. Most Perl packages
are so straight-forward to build that they are defined here directly, rather
than having a separate function for each package called from
<filename>perl-packages.nix</filename>. However, more complicated packages
should be put in a separate file, typically in
<filename>pkgs/development/perl-modules</filename>. Here is an example of the
former:
<programlisting>
ClassC3 = buildPerlPackage rec {
name = "Class-C3-0.21";
@ -28,74 +31,72 @@ ClassC3 = buildPerlPackage rec {
};
};
</programlisting>
Note the use of <literal>mirror://cpan/</literal>, and the
<literal>${name}</literal> in the URL definition to ensure that the
name attribute is consistent with the source that we’re actually
downloading. Perl packages are made available in
<filename>all-packages.nix</filename> through the variable
<varname>perlPackages</varname>. For instance, if you have a package
that needs <varname>ClassC3</varname>, you would typically write
Note the use of <literal>mirror://cpan/</literal>, and the
<literal>${name}</literal> in the URL definition to ensure that the name
attribute is consistent with the source that we’re actually downloading.
Perl packages are made available in <filename>all-packages.nix</filename>
through the variable <varname>perlPackages</varname>. For instance, if you
have a package that needs <varname>ClassC3</varname>, you would typically
write
<programlisting>
foo = import ../path/to/foo.nix {
inherit stdenv fetchurl ...;
inherit (perlPackages) ClassC3;
};
</programlisting>
in <filename>all-packages.nix</filename>. You can test building a
Perl package as follows:
in <filename>all-packages.nix</filename>. You can test building a Perl
package as follows:
<screen>
$ nix-build -A perlPackages.ClassC3
</screen>
<varname>buildPerlPackage</varname> adds <literal>perl-</literal> to
the start of the name attribute, so the package above is actually
called <literal>perl-Class-C3-0.21</literal>. So to install it, you
can say:
<varname>buildPerlPackage</varname> adds <literal>perl-</literal> to the
start of the name attribute, so the package above is actually called
<literal>perl-Class-C3-0.21</literal>. So to install it, you can say:
<screen>
$ nix-env -i perl-Class-C3
</screen>
(Of course you can also install using the attribute name: <literal>nix-env -i
-A perlPackages.ClassC3</literal>.)
</para>
(Of course you can also install using the attribute name:
<literal>nix-env -i -A perlPackages.ClassC3</literal>.)</para>
<para>So what does <varname>buildPerlPackage</varname> do? It does
the following:
<orderedlist>
<listitem><para>In the configure phase, it calls <literal>perl
Makefile.PL</literal> to generate a Makefile. You can set the
variable <varname>makeMakerFlags</varname> to pass flags to
<filename>Makefile.PL</filename></para></listitem>
<listitem><para>It adds the contents of the <envar>PERL5LIB</envar>
environment variable to <literal>#! .../bin/perl</literal> line of
Perl scripts as <literal>-I<replaceable>dir</replaceable></literal>
flags. This ensures that a script can find its
dependencies.</para></listitem>
<listitem><para>In the fixup phase, it writes the propagated build
inputs (<varname>propagatedBuildInputs</varname>) to the file
<filename>$out/nix-support/propagated-user-env-packages</filename>.
<command>nix-env</command> recursively installs all packages listed
in this file when you install a package that has it. This ensures
that a Perl package can find its dependencies.</para></listitem>
</orderedlist>
</para>
<para><varname>buildPerlPackage</varname> is built on top of
<varname>stdenv</varname>, so everything can be customised in the
usual way. For instance, the <literal>BerkeleyDB</literal> module has
a <varname>preConfigure</varname> hook to generate a configuration
file used by <filename>Makefile.PL</filename>:
<para>
So what does <varname>buildPerlPackage</varname> do? It does the following:
<orderedlist>
<listitem>
<para>
In the configure phase, it calls <literal>perl Makefile.PL</literal> to
generate a Makefile. You can set the variable
<varname>makeMakerFlags</varname> to pass flags to
<filename>Makefile.PL</filename>
</para>
</listitem>
<listitem>
<para>
It adds the contents of the <envar>PERL5LIB</envar> environment variable
to <literal>#! .../bin/perl</literal> line of Perl scripts as
<literal>-I<replaceable>dir</replaceable></literal> flags. This ensures
that a script can find its dependencies.
</para>
</listitem>
<listitem>
<para>
In the fixup phase, it writes the propagated build inputs
(<varname>propagatedBuildInputs</varname>) to the file
<filename>$out/nix-support/propagated-user-env-packages</filename>.
<command>nix-env</command> recursively installs all packages listed in
this file when you install a package that has it. This ensures that a Perl
package can find its dependencies.
</para>
</listitem>
</orderedlist>
</para>
<para>
<varname>buildPerlPackage</varname> is built on top of
<varname>stdenv</varname>, so everything can be customised in the usual way.
For instance, the <literal>BerkeleyDB</literal> module has a
<varname>preConfigure</varname> hook to generate a configuration file used by
<filename>Makefile.PL</filename>:
<programlisting>
{ buildPerlPackage, fetchurl, db }:
@ -113,18 +114,15 @@ buildPerlPackage rec {
'';
}
</programlisting>
</para>
</para>
<para>Dependencies on other Perl packages can be specified in the
<varname>buildInputs</varname> and
<varname>propagatedBuildInputs</varname> attributes. If something is
exclusively a build-time dependency, use
<varname>buildInputs</varname>; if it’s (also) a runtime dependency,
use <varname>propagatedBuildInputs</varname>. For instance, this
builds a Perl module that has runtime dependencies on a bunch of other
modules:
<para>
Dependencies on other Perl packages can be specified in the
<varname>buildInputs</varname> and <varname>propagatedBuildInputs</varname>
attributes. If something is exclusively a build-time dependency, use
<varname>buildInputs</varname>; if it’s (also) a runtime dependency, use
<varname>propagatedBuildInputs</varname>. For instance, this builds a Perl
module that has runtime dependencies on a bunch of other modules:
<programlisting>
ClassC3Componentised = buildPerlPackage rec {
name = "Class-C3-Componentised-1.0004";
@ -137,24 +135,26 @@ ClassC3Componentised = buildPerlPackage rec {
];
};
</programlisting>
</para>
</para>
<section xml:id="ssec-generation-from-CPAN">
<title>Generation from CPAN</title>
<section xml:id="ssec-generation-from-CPAN"><title>Generation from CPAN</title>
<para>Nix expressions for Perl packages can be generated (almost)
automatically from CPAN. This is done by the program
<command>nix-generate-from-cpan</command>, which can be installed
as follows:</para>
<para>
Nix expressions for Perl packages can be generated (almost) automatically
from CPAN. This is done by the program
<command>nix-generate-from-cpan</command>, which can be installed as
follows:
</para>
<screen>
$ nix-env -i nix-generate-from-cpan
</screen>
<para>This program takes a Perl module name, looks it up on CPAN,
fetches and unpacks the corresponding package, and prints a Nix
expression on standard output. For example:
<para>
This program takes a Perl module name, looks it up on CPAN, fetches and
unpacks the corresponding package, and prints a Nix expression on standard
output. For example:
<screen>
$ nix-generate-from-cpan XML::Simple
XMLSimple = buildPerlPackage rec {
@ -170,26 +170,23 @@ $ nix-generate-from-cpan XML::Simple
};
};
</screen>
The output can be pasted into
<filename>pkgs/top-level/perl-packages.nix</filename> or wherever else you
need it.
</para>
</section>
The output can be pasted into
<filename>pkgs/top-level/perl-packages.nix</filename> or wherever else
you need it.</para>
<section xml:id="ssec-perl-cross-compilation">
<title>Cross-compiling modules</title>
<para>
Nixpkgs has experimental support for cross-compiling Perl modules. In many
cases, it will just work out of the box, even for modules with native
extensions. Sometimes, however, the Makefile.PL for a module may
(indirectly) import a native module. In that case, you will need to make a
stub for that module that will satisfy the Makefile.PL and install it into
<filename>lib/perl5/site_perl/cross_perl/${perl.version}</filename>. See the
<varname>postInstall</varname> for <varname>DBI</varname> for an example.
</para>
</section>
</section>
<section xml:id="ssec-perl-cross-compilation"><title>Cross-compiling modules</title>
<para>Nixpkgs has experimental support for cross-compiling Perl
modules. In many cases, it will just work out of the box, even for
modules with native extensions. Sometimes, however, the Makefile.PL
for a module may (indirectly) import a native module. In that case,
you will need to make a stub for that module that will satisfy the
Makefile.PL and install it into
<filename>lib/perl5/site_perl/cross_perl/${perl.version}</filename>.
See the <varname>postInstall</varname> for <varname>DBI</varname> for
an example.</para>
</section>
</section>

112
doc/languages-frameworks/qt.xml
View File

@ -1,58 +1,74 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-qt">
<title>Qt</title>
<title>Qt</title>
<para>
Qt is a comprehensive desktop and mobile application development toolkit for
C++. Legacy support is available for Qt 3 and Qt 4, but all current
development uses Qt 5. The Qt 5 packages in Nixpkgs are updated frequently to
take advantage of new features, but older versions are typically retained
until their support window ends. The most important consideration in
packaging Qt-based software is ensuring that each package and all its
dependencies use the same version of Qt 5; this consideration motivates most
of the tools described below.
</para>
<para>
Qt is a comprehensive desktop and mobile application development toolkit for C++.
Legacy support is available for Qt 3 and Qt 4, but all current development uses Qt 5.
The Qt 5 packages in Nixpkgs are updated frequently to take advantage of new features,
but older versions are typically retained until their support window ends.
The most important consideration in packaging Qt-based software is ensuring that each package and all its dependencies use the same version of Qt 5;
this consideration motivates most of the tools described below.
</para>
<section xml:id="ssec-qt-libraries">
<title>Packaging Libraries for Nixpkgs</title>
<section xml:id="ssec-qt-libraries"><title>Packaging Libraries for Nixpkgs</title>
<para>
Whenever possible, libraries that use Qt 5 should be built with each
available version. Packages providing libraries should be added to the
top-level function <varname>mkLibsForQt5</varname>, which is used to build a
set of libraries for every Qt 5 version. A special
<varname>callPackage</varname> function is used in this scope to ensure that
the entire dependency tree uses the same Qt 5 version. Import dependencies
unqualified, i.e., <literal>qtbase</literal> not
<literal>qt5.qtbase</literal>. <emphasis>Do not</emphasis> import a package
set such as <literal>qt5</literal> or <literal>libsForQt5</literal>.
</para>
<para>
Whenever possible, libraries that use Qt 5 should be built with each available version.
Packages providing libraries should be added to the top-level function <varname>mkLibsForQt5</varname>,
which is used to build a set of libraries for every Qt 5 version.
A special <varname>callPackage</varname> function is used in this scope to ensure that the entire dependency tree uses the same Qt 5 version.
Import dependencies unqualified, i.e., <literal>qtbase</literal> not <literal>qt5.qtbase</literal>.
<emphasis>Do not</emphasis> import a package set such as <literal>qt5</literal> or <literal>libsForQt5</literal>.
</para>
<para>
If a library does not support a particular version of Qt 5, it is best to
mark it as broken by setting its <literal>meta.broken</literal> attribute. A
package may be marked broken for certain versions by testing the
<literal>qtbase.version</literal> attribute, which will always give the
current Qt 5 version.
</para>
</section>
<para>
If a library does not support a particular version of Qt 5, it is best to mark it as broken by setting its <literal>meta.broken</literal> attribute.
A package may be marked broken for certain versions by testing the <literal>qtbase.version</literal> attribute, which will always give the current Qt 5 version.
</para>
<section xml:id="ssec-qt-applications">
<title>Packaging Applications for Nixpkgs</title>
<para>
Call your application expression using
<literal>libsForQt5.callPackage</literal> instead of
<literal>callPackage</literal>. Import dependencies unqualified, i.e.,
<literal>qtbase</literal> not <literal>qt5.qtbase</literal>. <emphasis>Do
not</emphasis> import a package set such as <literal>qt5</literal> or
<literal>libsForQt5</literal>.
</para>
<para>
Qt 5 maintains strict backward compatibility, so it is generally best to
build an application package against the latest version using the
<varname>libsForQt5</varname> library set. In case a package does not build
with the latest Qt version, it is possible to pick a set pinned to a
particular version, e.g. <varname>libsForQt55</varname> for Qt 5.5, if that
is the latest version the package supports. If a package must be pinned to
an older Qt version, be sure to file a bug upstream; because Qt is strictly
backwards-compatible, any incompatibility is by definition a bug in the
application.
</para>
<para>
When testing applications in Nixpkgs, it is a common practice to build the
package with <literal>nix-build</literal> and run it using the created
symbolic link. This will not work with Qt applications, however, because
they have many hard runtime requirements that can only be guaranteed if the
package is actually installed. To test a Qt application, install it with
<literal>nix-env</literal> or run it inside <literal>nix-shell</literal>.
</para>
</section>
</section>
<section xml:id="ssec-qt-applications"><title>Packaging Applications for Nixpkgs</title>
<para>
Call your application expression using <literal>libsForQt5.callPackage</literal> instead of <literal>callPackage</literal>.
Import dependencies unqualified, i.e., <literal>qtbase</literal> not <literal>qt5.qtbase</literal>.
<emphasis>Do not</emphasis> import a package set such as <literal>qt5</literal> or <literal>libsForQt5</literal>.
</para>
<para>
Qt 5 maintains strict backward compatibility, so it is generally best to build an application package against the latest version using the <varname>libsForQt5</varname> library set.
In case a package does not build with the latest Qt version, it is possible to pick a set pinned to a particular version, e.g. <varname>libsForQt55</varname> for Qt 5.5, if that is the latest version the package supports.
If a package must be pinned to an older Qt version, be sure to file a bug upstream;
because Qt is strictly backwards-compatible, any incompatibility is by definition a bug in the application.
</para>
<para>
When testing applications in Nixpkgs, it is a common practice to build the package with <literal>nix-build</literal> and run it using the created symbolic link.
This will not work with Qt applications, however, because they have many hard runtime requirements that can only be guaranteed if the package is actually installed.
To test a Qt application, install it with <literal>nix-env</literal> or run it inside <literal>nix-shell</literal>.
</para>
</section>
</section>

90
doc/languages-frameworks/ruby.xml
View File

@ -1,17 +1,19 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-ruby">
<title>Ruby</title>
<title>Ruby</title>
<para>
There currently is support to bundle applications that are packaged as Ruby
gems. The utility "bundix" allows you to write a
<filename>Gemfile</filename>, let bundler create a
<filename>Gemfile.lock</filename>, and then convert this into a nix
expression that contains all Gem dependencies automatically.
</para>
<para>There currently is support to bundle applications that are packaged as
Ruby gems. The utility "bundix" allows you to write a
<filename>Gemfile</filename>, let bundler create a
<filename>Gemfile.lock</filename>, and then convert this into a nix
expression that contains all Gem dependencies automatically.
</para>
<para>For example, to package sensu, we did:</para>
<para>
For example, to package sensu, we did:
</para>
<screen>
<![CDATA[$ cd pkgs/servers/monitoring
@ -42,17 +44,18 @@ bundlerEnv rec {
}]]>
</screen>
<para>Please check in the <filename>Gemfile</filename>,
<filename>Gemfile.lock</filename> and the
<filename>gemset.nix</filename> so future updates can be run easily.
</para>
<para>
Please check in the <filename>Gemfile</filename>,
<filename>Gemfile.lock</filename> and the <filename>gemset.nix</filename> so
future updates can be run easily.
</para>
<para>For tools written in Ruby - i.e. where the desire is to install
a package and then execute e.g. <command>rake</command> at the command
line, there is an alternative builder called <literal>bundlerApp</literal>.
Set up the <filename>gemset.nix</filename> the same way, and then, for
example:
</para>
<para>
For tools written in Ruby - i.e. where the desire is to install a package and
then execute e.g. <command>rake</command> at the command line, there is an
alternative builder called <literal>bundlerApp</literal>. Set up the
<filename>gemset.nix</filename> the same way, and then, for example:
</para>
<screen>
<![CDATA[{ lib, bundlerApp }:
@ -72,31 +75,31 @@ bundlerApp {
}]]>
</screen>
<para>The chief advantage of <literal>bundlerApp</literal> over
<literal>bundlerEnv</literal> is the executables introduced in the
environment are precisely those selected in the <literal>exes</literal>
list, as opposed to <literal>bundlerEnv</literal> which adds all the
executables made available by gems in the gemset, which can mean e.g.
<command>rspec</command> or <command>rake</command> in unpredictable
versions available from various packages.
</para>
<para>
The chief advantage of <literal>bundlerApp</literal> over
<literal>bundlerEnv</literal> is the executables introduced in the
environment are precisely those selected in the <literal>exes</literal> list,
as opposed to <literal>bundlerEnv</literal> which adds all the executables
made available by gems in the gemset, which can mean e.g.
<command>rspec</command> or <command>rake</command> in unpredictable versions
available from various packages.
</para>
<para>Resulting derivations for both builders also have two helpful
attributes, <literal>env</literal> and <literal>wrappedRuby</literal>.
The first one allows one to quickly drop into
<command>nix-shell</command> with the specified environment present.
E.g. <command>nix-shell -A sensu.env</command> would give you an
environment with Ruby preset so it has all the libraries necessary
for <literal>sensu</literal> in its paths. The second one can be
used to make derivations from custom Ruby scripts which have
<filename>Gemfile</filename>s with their dependencies specified. It is
a derivation with <command>ruby</command> wrapped so it can find all
the needed dependencies. For example, to make a derivation
<literal>my-script</literal> for a <filename>my-script.rb</filename>
(which should be placed in <filename>bin</filename>) you should run
<command>bundix</command> as specified above and then use
<literal>bundlerEnv</literal> like this:
</para>
<para>
Resulting derivations for both builders also have two helpful attributes,
<literal>env</literal> and <literal>wrappedRuby</literal>. The first one
allows one to quickly drop into <command>nix-shell</command> with the
specified environment present. E.g. <command>nix-shell -A sensu.env</command>
would give you an environment with Ruby preset so it has all the libraries
necessary for <literal>sensu</literal> in its paths. The second one can be
used to make derivations from custom Ruby scripts which have
<filename>Gemfile</filename>s with their dependencies specified. It is a
derivation with <command>ruby</command> wrapped so it can find all the needed
dependencies. For example, to make a derivation <literal>my-script</literal>
for a <filename>my-script.rb</filename> (which should be placed in
<filename>bin</filename>) you should run <command>bundix</command> as
specified above and then use <literal>bundlerEnv</literal> like this:
</para>
<programlisting>
<![CDATA[let env = bundlerEnv {
@ -118,5 +121,4 @@ in stdenv.mkDerivation {
'';
}]]>
</programlisting>
</section>

108
doc/languages-frameworks/texlive.xml
View File

@ -1,27 +1,42 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-texlive">
<title>TeX Live</title>
<title>TeX Live</title>
<para>
Since release 15.09 there is a new TeX Live packaging that lives entirely
under attribute <varname>texlive</varname>.
</para>
<section>
<title>User's guide</title>
<para>Since release 15.09 there is a new TeX Live packaging that lives entirely under attribute <varname>texlive</varname>.</para>
<section><title>User's guide</title>
<itemizedlist>
<listitem><para>
For basic usage just pull <varname>texlive.combined.scheme-basic</varname> for an environment with basic LaTeX support.</para></listitem>
<listitem><para>
It typically won't work to use separately installed packages together.
Instead, you can build a custom set of packages like this:
<programlisting>
<listitem>
<para>
For basic usage just pull <varname>texlive.combined.scheme-basic</varname>
for an environment with basic LaTeX support.
</para>
</listitem>
<listitem>
<para>
It typically won't work to use separately installed packages together.
Instead, you can build a custom set of packages like this:
<programlisting>
texlive.combine {
inherit (texlive) scheme-small collection-langkorean algorithms cm-super;
}
</programlisting>
There are all the schemes, collections and a few thousand packages, as defined upstream (perhaps with tiny differences).
</para></listitem>
<listitem><para>
By default you only get executables and files needed during runtime, and a little documentation for the core packages. To change that, you need to add <varname>pkgFilter</varname> function to <varname>combine</varname>.
<programlisting>
There are all the schemes, collections and a few thousand packages, as
defined upstream (perhaps with tiny differences).
</para>
</listitem>
<listitem>
<para>
By default you only get executables and files needed during runtime, and a
little documentation for the core packages. To change that, you need to
add <varname>pkgFilter</varname> function to <varname>combine</varname>.
<programlisting>
texlive.combine {
# inherit (texlive) whatever-you-want;
pkgFilter = pkg:
@ -30,34 +45,55 @@ texlive.combine {
# there are also other attributes: version, name
}
</programlisting>
</para></listitem>
<listitem><para>
You can list packages e.g. by <command>nix-repl</command>.
<programlisting>
</para>
</listitem>
<listitem>
<para>
You can list packages e.g. by <command>nix-repl</command>.
<programlisting>
$ nix-repl
nix-repl> :l &lt;nixpkgs>
nix-repl> texlive.collection-&lt;TAB>
</programlisting>
</para></listitem>
<listitem><para>
Note that the wrapper assumes that the result has a chance to be useful. For example, the core executables should be present, as well as some core data files. The supported way of ensuring this is by including some scheme, for example <varname>scheme-basic</varname>, into the combination.
</para></listitem>
</para>
</listitem>
<listitem>
<para>
Note that the wrapper assumes that the result has a chance to be useful.
For example, the core executables should be present, as well as some core
data files. The supported way of ensuring this is by including some
scheme, for example <varname>scheme-basic</varname>, into the combination.
</para>
</listitem>
</itemizedlist>
</section>
</section>
<section>
<title>Known problems</title>
<section><title>Known problems</title>
<itemizedlist>
<listitem><para>
Some tools are still missing, e.g. luajittex;</para></listitem>
<listitem><para>
some apps aren't packaged/tested yet (asymptote, biber, etc.);</para></listitem>
<listitem><para>
feature/bug: when a package is rejected by <varname>pkgFilter</varname>, its dependencies are still propagated;</para></listitem>
<listitem><para>
in case of any bugs or feature requests, file a github issue or better a pull request and /cc @vcunat.</para></listitem>
<listitem>
<para>
Some tools are still missing, e.g. luajittex;
</para>
</listitem>
<listitem>
<para>
some apps aren't packaged/tested yet (asymptote, biber, etc.);
</para>
</listitem>
<listitem>
<para>
feature/bug: when a package is rejected by <varname>pkgFilter</varname>,
its dependencies are still propagated;
</para>
</listitem>
<listitem>
<para>
in case of any bugs or feature requests, file a github issue or better a
pull request and /cc @vcunat.
</para>
</listitem>
</itemizedlist>
</section>
</section>
</section>

47
doc/manual.xml
View File

@ -1,29 +1,24 @@
<book xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude">
<info>
<title>Nixpkgs Contributors Guide</title>
<subtitle>Version <xi:include href=".version" parse="text" /></subtitle>
</info>
<xi:include href="introduction.chapter.xml" />
<xi:include href="quick-start.xml" />
<xi:include href="stdenv.xml" />
<xi:include href="multiple-output.xml" />
<xi:include href="cross-compilation.xml" />
<xi:include href="configuration.xml" />
<xi:include href="functions.xml" />
<xi:include href="meta.xml" />
<xi:include href="languages-frameworks/index.xml" />
<xi:include href="platform-notes.xml" />
<xi:include href="package-notes.xml" />
<xi:include href="overlays.xml" />
<xi:include href="coding-conventions.xml" />
<xi:include href="submitting-changes.xml" />
<xi:include href="reviewing-contributions.xml" />
<xi:include href="contributing.xml" />
<info>
<title>Nixpkgs Contributors Guide</title>
<subtitle>Version <xi:include href=".version" parse="text" />
</subtitle>
</info>
<xi:include href="introduction.chapter.xml" />
<xi:include href="quick-start.xml" />
<xi:include href="stdenv.xml" />
<xi:include href="multiple-output.xml" />
<xi:include href="cross-compilation.xml" />
<xi:include href="configuration.xml" />
<xi:include href="functions.xml" />
<xi:include href="meta.xml" />
<xi:include href="languages-frameworks/index.xml" />
<xi:include href="platform-notes.xml" />
<xi:include href="package-notes.xml" />
<xi:include href="overlays.xml" />
<xi:include href="coding-conventions.xml" />
<xi:include href="submitting-changes.xml" />
<xi:include href="reviewing-contributions.xml" />
<xi:include href="contributing.xml" />
</book>

540
doc/meta.xml
View File

@ -1,14 +1,12 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-meta">
<title>Meta-attributes</title>
<para>Nix packages can declare <emphasis>meta-attributes</emphasis>
that contain information about a package such as a description, its
homepage, its license, and so on. For instance, the GNU Hello package
has a <varname>meta</varname> declaration like this:
<title>Meta-attributes</title>
<para>
Nix packages can declare <emphasis>meta-attributes</emphasis> that contain
information about a package such as a description, its homepage, its license,
and so on. For instance, the GNU Hello package has a <varname>meta</varname>
declaration like this:
<programlisting>
meta = {
description = "A program that produces a familiar, friendly greeting";
@ -22,16 +20,15 @@ meta = {
platforms = stdenv.lib.platforms.all;
};
</programlisting>
</para>
<para>Meta-attributes are not passed to the builder of the package.
Thus, a change to a meta-attribute doesn’t trigger a recompilation of
the package. The value of a meta-attribute must be a string.</para>
<para>The meta-attributes of a package can be queried from the
command-line using <command>nix-env</command>:
</para>
<para>
Meta-attributes are not passed to the builder of the package. Thus, a change
to a meta-attribute doesn’t trigger a recompilation of the package. The
value of a meta-attribute must be a string.
</para>
<para>
The meta-attributes of a package can be queried from the command-line using
<command>nix-env</command>:
<screen>
$ nix-env -qa hello --json
{
@ -70,252 +67,299 @@ $ nix-env -qa hello --json
</screen>
<command>nix-env</command> knows about the
<varname>description</varname> field specifically:
<command>nix-env</command> knows about the <varname>description</varname>
field specifically:
<screen>
$ nix-env -qa hello --description
hello-2.3 A program that produces a familiar, friendly greeting
</screen>
</para>
<section xml:id="sec-standard-meta-attributes">
<title>Standard meta-attributes</title>
</para>
<para>
It is expected that each meta-attribute is one of the following:
</para>
<section xml:id="sec-standard-meta-attributes"><title>Standard
meta-attributes</title>
<para>It is expected that each meta-attribute is one of the following:</para>
<variablelist>
<varlistentry>
<term><varname>description</varname></term>
<listitem><para>A short (one-line) description of the package.
This is shown by <command>nix-env -q --description</command> and
also on the Nixpkgs release pages.</para>
<para>Don’t include a period at the end. Don’t include newline
characters. Capitalise the first character. For brevity, don’t
repeat the name of package — just describe what it does.</para>
<para>Wrong: <literal>"libpng is a library that allows you to decode PNG images."</literal></para>
<para>Right: <literal>"A library for decoding PNG images"</literal></para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>longDescription</varname></term>
<listitem><para>An arbitrarily long description of the
package.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>branch</varname></term>
<listitem><para>Release branch. Used to specify that a package is not
going to receive updates that are not in this branch; for example, Linux
kernel 3.0 is supposed to be updated to 3.0.X, not 3.1.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>homepage</varname></term>
<listitem><para>The package’s homepage. Example:
<literal>http://www.gnu.org/software/hello/manual/</literal></para></listitem>
</varlistentry>
<varlistentry>
<term><varname>downloadPage</varname></term>
<listitem><para>The page where a link to the current version can be found. Example:
<literal>http://ftp.gnu.org/gnu/hello/</literal></para></listitem>
</varlistentry>
<varlistentry>
<term><varname>license</varname></term>
<variablelist>
<varlistentry>
<term><varname>description</varname>
</term>
<listitem>
<para>
The license, or licenses, for the package. One from the attribute set
defined in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
<filename>nixpkgs/lib/licenses.nix</filename></link>. At this moment
using both a list of licenses and a single license is valid. If the
license field is in the form of a list representation, then it means
that parts of the package are licensed differently. Each license
should preferably be referenced by their attribute. The non-list
attribute value can also be a space delimited string representation of
the contained attribute shortNames or spdxIds. The following are all valid
examples:
<itemizedlist>
<listitem><para>Single license referenced by attribute (preferred)
<literal>stdenv.lib.licenses.gpl3</literal>.
</para></listitem>
<listitem><para>Single license referenced by its attribute shortName (frowned upon)
<literal>"gpl3"</literal>.
</para></listitem>
<listitem><para>Single license referenced by its attribute spdxId (frowned upon)
<literal>"GPL-3.0"</literal>.
</para></listitem>
<listitem><para>Multiple licenses referenced by attribute (preferred)
<literal>with stdenv.lib.licenses; [ asl20 free ofl ]</literal>.
</para></listitem>
<listitem><para>Multiple licenses referenced as a space delimited string of attribute shortNames (frowned upon)
<literal>"asl20 free ofl"</literal>.
</para></listitem>
</itemizedlist>
For details, see <xref linkend='sec-meta-license'/>.
</para>
<para>
A short (one-line) description of the package. This is shown by
<command>nix-env -q --description</command> and also on the Nixpkgs
release pages.
</para>
<para>
Don’t include a period at the end. Don’t include newline characters.
Capitalise the first character. For brevity, don’t repeat the name of
package — just describe what it does.
</para>
<para>
Wrong: <literal>"libpng is a library that allows you to decode PNG
images."</literal>
</para>
<para>
Right: <literal>"A library for decoding PNG images"</literal>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>maintainers</varname></term>
<listitem><para>A list of names and e-mail addresses of the
maintainers of this Nix expression. If
you would like to be a maintainer of a package, you may want to add
yourself to <link
</varlistentry>
<varlistentry>
<term><varname>longDescription</varname>
</term>
<listitem>
<para>
An arbitrarily long description of the package.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>branch</varname>
</term>
<listitem>
<para>
Release branch. Used to specify that a package is not going to receive
updates that are not in this branch; for example, Linux kernel 3.0 is
supposed to be updated to 3.0.X, not 3.1.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>homepage</varname>
</term>
<listitem>
<para>
The package’s homepage. Example:
<literal>http://www.gnu.org/software/hello/manual/</literal>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>downloadPage</varname>
</term>
<listitem>
<para>
The page where a link to the current version can be found. Example:
<literal>http://ftp.gnu.org/gnu/hello/</literal>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>license</varname>
</term>
<listitem>
<para>
The license, or licenses, for the package. One from the attribute set
defined in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
<filename>nixpkgs/lib/licenses.nix</filename></link>. At this moment
using both a list of licenses and a single license is valid. If the
license field is in the form of a list representation, then it means that
parts of the package are licensed differently. Each license should
preferably be referenced by their attribute. The non-list attribute value
can also be a space delimited string representation of the contained
attribute shortNames or spdxIds. The following are all valid examples:
<itemizedlist>
<listitem>
<para>
Single license referenced by attribute (preferred)
<literal>stdenv.lib.licenses.gpl3</literal>.
</para>
</listitem>
<listitem>
<para>
Single license referenced by its attribute shortName (frowned upon)
<literal>"gpl3"</literal>.
</para>
</listitem>
<listitem>
<para>
Single license referenced by its attribute spdxId (frowned upon)
<literal>"GPL-3.0"</literal>.
</para>
</listitem>
<listitem>
<para>
Multiple licenses referenced by attribute (preferred) <literal>with
stdenv.lib.licenses; [ asl20 free ofl ]</literal>.
</para>
</listitem>
<listitem>
<para>
Multiple licenses referenced as a space delimited string of attribute
shortNames (frowned upon) <literal>"asl20 free ofl"</literal>.
</para>
</listitem>
</itemizedlist>
For details, see <xref linkend='sec-meta-license'/>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>maintainers</varname>
</term>
<listitem>
<para>
A list of names and e-mail addresses of the maintainers of this Nix
expression. If you would like to be a maintainer of a package, you may
want to add yourself to
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/maintainers/maintainer-list.nix"><filename>nixpkgs/maintainers/maintainer-list.nix</filename></link>
and write something like <literal>[ stdenv.lib.maintainers.alice
stdenv.lib.maintainers.bob ]</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>priority</varname></term>
<listitem><para>The <emphasis>priority</emphasis> of the package,
used by <command>nix-env</command> to resolve file name conflicts
between packages. See the Nix manual page for
<command>nix-env</command> for details. Example:
<literal>"10"</literal> (a low-priority
package).</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>platforms</varname></term>
<listitem><para>The list of Nix platform types on which the
package is supported. Hydra builds packages according to the
platform specified. If no platform is specified, the package does
not have prebuilt binaries. An example is:
and write something like <literal>[ stdenv.lib.maintainers.alice
stdenv.lib.maintainers.bob ]</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>priority</varname>
</term>
<listitem>
<para>
The <emphasis>priority</emphasis> of the package, used by
<command>nix-env</command> to resolve file name conflicts between
packages. See the Nix manual page for <command>nix-env</command> for
details. Example: <literal>"10"</literal> (a low-priority package).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>platforms</varname>
</term>
<listitem>
<para>
The list of Nix platform types on which the package is supported. Hydra
builds packages according to the platform specified. If no platform is
specified, the package does not have prebuilt binaries. An example is:
<programlisting>
meta.platforms = stdenv.lib.platforms.linux;
</programlisting>
Attribute Set <varname>stdenv.lib.platforms</varname> defines
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/systems/doubles.nix">
various common lists</link> of platforms types.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>hydraPlatforms</varname></term>
<listitem><para>The list of Nix platform types for which the Hydra
instance at <literal>hydra.nixos.org</literal> will build the
package. (Hydra is the Nix-based continuous build system.) It
defaults to the value of <varname>meta.platforms</varname>. Thus,
the only reason to set <varname>meta.hydraPlatforms</varname> is
if you want <literal>hydra.nixos.org</literal> to build the
package on a subset of <varname>meta.platforms</varname>, or not
at all, e.g.
Attribute Set <varname>stdenv.lib.platforms</varname> defines
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/systems/doubles.nix">
various common lists</link> of platforms types.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>hydraPlatforms</varname>
</term>
<listitem>
<para>
The list of Nix platform types for which the Hydra instance at
<literal>hydra.nixos.org</literal> will build the package. (Hydra is the
Nix-based continuous build system.) It defaults to the value of
<varname>meta.platforms</varname>. Thus, the only reason to set
<varname>meta.hydraPlatforms</varname> is if you want
<literal>hydra.nixos.org</literal> to build the package on a subset of
<varname>meta.platforms</varname>, or not at all, e.g.
<programlisting>
meta.platforms = stdenv.lib.platforms.linux;
meta.hydraPlatforms = [];
</programlisting>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>broken</varname>
</term>
<listitem>
<para>
If set to <literal>true</literal>, the package is marked as “broken”,
meaning that it won’t show up in <literal>nix-env -qa</literal>, and
cannot be built or installed. Such packages should be removed from
Nixpkgs eventually unless they are fixed.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>updateWalker</varname>
</term>
<listitem>
<para>
If set to <literal>true</literal>, the package is tested to be updated
correctly by the <literal>update-walker.sh</literal> script without
additional settings. Such packages have <varname>meta.version</varname>
set and their homepage (or the page specified by
<varname>meta.downloadPage</varname>) contains a direct link to the
package tarball.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section xml:id="sec-meta-license">
<title>Licenses</title>
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>broken</varname></term>
<listitem><para>If set to <literal>true</literal>, the package is
marked as “broken”, meaning that it won’t show up in
<literal>nix-env -qa</literal>, and cannot be built or installed.
Such packages should be removed from Nixpkgs eventually unless
they are fixed.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>updateWalker</varname></term>
<listitem><para>If set to <literal>true</literal>, the package is
tested to be updated correctly by the <literal>update-walker.sh</literal>
script without additional settings. Such packages have
<varname>meta.version</varname> set and their homepage (or
the page specified by <varname>meta.downloadPage</varname>) contains
a direct link to the package tarball.</para></listitem>
</varlistentry>
</variablelist>
</section>
<section xml:id="sec-meta-license"><title>Licenses</title>
<para>The <varname>meta.license</varname> attribute should preferrably contain
a value from <varname>stdenv.lib.licenses</varname> defined in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
<filename>nixpkgs/lib/licenses.nix</filename></link>,
or in-place license description of the same format if the license is
unlikely to be useful in another expression.</para>
<para>Although it's typically better to indicate the specific license,
a few generic options are available:
<variablelist>
<varlistentry>
<term><varname>stdenv.lib.licenses.free</varname>,
<varname>"free"</varname></term>
<listitem><para>Catch-all for free software licenses not listed
above.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfreeRedistributable</varname>,
<varname>"unfree-redistributable"</varname></term>
<listitem><para>Unfree package that can be redistributed in binary
form. That is, it’s legal to redistribute the
<emphasis>output</emphasis> of the derivation. This means that
the package can be included in the Nixpkgs
channel.</para>
<para>Sometimes proprietary software can only be redistributed
unmodified. Make sure the builder doesn’t actually modify the
original binaries; otherwise we’re breaking the license. For
instance, the NVIDIA X11 drivers can be redistributed unmodified,
but our builder applies <command>patchelf</command> to make them
work. Thus, its license is <varname>"unfree"</varname> and it
cannot be included in the Nixpkgs channel.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfree</varname>,
<varname>"unfree"</varname></term>
<listitem><para>Unfree package that cannot be redistributed. You
can build it yourself, but you cannot redistribute the output of
the derivation. Thus it cannot be included in the Nixpkgs
channel.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfreeRedistributableFirmware</varname>,
<varname>"unfree-redistributable-firmware"</varname></term>
<listitem><para>This package supplies unfree, redistributable
firmware. This is a separate value from
<varname>unfree-redistributable</varname> because not everybody
cares whether firmware is free.</para></listitem>
</varlistentry>
</variablelist>
</para>
</section>
<para>
The <varname>meta.license</varname> attribute should preferrably contain a
value from <varname>stdenv.lib.licenses</varname> defined in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
<filename>nixpkgs/lib/licenses.nix</filename></link>, or in-place license
description of the same format if the license is unlikely to be useful in
another expression.
</para>
<para>
Although it's typically better to indicate the specific license, a few
generic options are available:
<variablelist>
<varlistentry>
<term><varname>stdenv.lib.licenses.free</varname>,
<varname>"free"</varname>
</term>
<listitem>
<para>
Catch-all for free software licenses not listed above.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfreeRedistributable</varname>,
<varname>"unfree-redistributable"</varname>
</term>
<listitem>
<para>
Unfree package that can be redistributed in binary form. That is, it’s
legal to redistribute the <emphasis>output</emphasis> of the derivation.
This means that the package can be included in the Nixpkgs channel.
</para>
<para>
Sometimes proprietary software can only be redistributed unmodified.
Make sure the builder doesn’t actually modify the original binaries;
otherwise we’re breaking the license. For instance, the NVIDIA X11
drivers can be redistributed unmodified, but our builder applies
<command>patchelf</command> to make them work. Thus, its license is
<varname>"unfree"</varname> and it cannot be included in the Nixpkgs
channel.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfree</varname>,
<varname>"unfree"</varname>
</term>
<listitem>
<para>
Unfree package that cannot be redistributed. You can build it yourself,
but you cannot redistribute the output of the derivation. Thus it cannot
be included in the Nixpkgs channel.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfreeRedistributableFirmware</varname>,
<varname>"unfree-redistributable-firmware"</varname>
</term>
<listitem>
<para>
This package supplies unfree, redistributable firmware. This is a
separate value from <varname>unfree-redistributable</varname> because
not everybody cares whether firmware is free.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</section>
</chapter>

380
doc/multiple-output.xml
View File

@ -5,105 +5,319 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-multiple-output">
<title>Multiple-output packages</title>
<section>
<title>Introduction</title>
<title>Multiple-output packages</title>
<para>
The Nix language allows a derivation to produce multiple outputs, which is
similar to what is utilized by other Linux distribution packaging systems.
The outputs reside in separate nix store paths, so they can be mostly
handled independently of each other, including passing to build inputs,
garbage collection or binary substitution. The exception is that building
from source always produces all the outputs.
</para>
<section><title>Introduction</title>
<para>The Nix language allows a derivation to produce multiple outputs, which is similar to what is utilized by other Linux distribution packaging systems. The outputs reside in separate nix store paths, so they can be mostly handled independently of each other, including passing to build inputs, garbage collection or binary substitution. The exception is that building from source always produces all the outputs.</para>
<para>The main motivation is to save disk space by reducing runtime closure sizes; consequently also sizes of substituted binaries get reduced. Splitting can be used to have more granular runtime dependencies, for example the typical reduction is to split away development-only files, as those are typically not needed during runtime. As a result, closure sizes of many packages can get reduced to a half or even much less.</para>
<note><para>The reduction effects could be instead achieved by building the parts in completely separate derivations. That would often additionally reduce build-time closures, but it tends to be much harder to write such derivations, as build systems typically assume all parts are being built at once. This compromise approach of single source package producing multiple binary packages is also utilized often by rpm and deb.</para></note>
</section>
<para>
The main motivation is to save disk space by reducing runtime closure sizes;
consequently also sizes of substituted binaries get reduced. Splitting can
be used to have more granular runtime dependencies, for example the typical
reduction is to split away development-only files, as those are typically
not needed during runtime. As a result, closure sizes of many packages can
get reduced to a half or even much less.
</para>
<note>
<para>
The reduction effects could be instead achieved by building the parts in
completely separate derivations. That would often additionally reduce
build-time closures, but it tends to be much harder to write such
derivations, as build systems typically assume all parts are being built at
once. This compromise approach of single source package producing multiple
binary packages is also utilized often by rpm and deb.
</para>
</note>
</section>
<section>
<title>Installing a split package</title>
<para>
When installing a package via <varname>systemPackages</varname> or
<command>nix-env</command> you have several options:
</para>
<section><title>Installing a split package</title>
<para>When installing a package via <varname>systemPackages</varname> or <command>nix-env</command> you have several options:</para>
<itemizedlist>
<listitem><para>You can install particular outputs explicitly, as each is available in the Nix language as an attribute of the package. The <varname>outputs</varname> attribute contains a list of output names.</para></listitem>
<listitem><para>You can let it use the default outputs. These are handled by <varname>meta.outputsToInstall</varname> attribute that contains a list of output names.</para>
<para>TODO: more about tweaking the attribute, etc.</para></listitem>
<listitem><para>NixOS provides configuration option <varname>environment.extraOutputsToInstall</varname> that allows adding extra outputs of <varname>environment.systemPackages</varname> atop the default ones. It's mainly meant for documentation and debug symbols, and it's also modified by specific options.</para>
<note><para>At this moment there is no similar configurability for packages installed by <command>nix-env</command>. You can still use approach from <xref linkend="sec-modify-via-packageOverrides" /> to override <varname>meta.outputsToInstall</varname> attributes, but that's a rather inconvenient way.</para></note>
</listitem>
<listitem>
<para>
You can install particular outputs explicitly, as each is available in the
Nix language as an attribute of the package. The
<varname>outputs</varname> attribute contains a list of output names.
</para>
</listitem>
<listitem>
<para>
You can let it use the default outputs. These are handled by
<varname>meta.outputsToInstall</varname> attribute that contains a list of
output names.
</para>
<para>
TODO: more about tweaking the attribute, etc.
</para>
</listitem>
<listitem>
<para>
NixOS provides configuration option
<varname>environment.extraOutputsToInstall</varname> that allows adding
extra outputs of <varname>environment.systemPackages</varname> atop the
default ones. It's mainly meant for documentation and debug symbols, and
it's also modified by specific options.
</para>
<note>
<para>
At this moment there is no similar configurability for packages installed
by <command>nix-env</command>. You can still use approach from
<xref linkend="sec-modify-via-packageOverrides" /> to override
<varname>meta.outputsToInstall</varname> attributes, but that's a rather
inconvenient way.
</para>
</note>
</listitem>
</itemizedlist>
</section>
</section>
<section>
<title>Using a split package</title>
<section><title>Using a split package</title>
<para>In the Nix language the individual outputs can be reached explicitly as attributes, e.g. <varname>coreutils.info</varname>, but the typical case is just using packages as build inputs.</para>
<para>When a multiple-output derivation gets into a build input of another derivation, the <varname>dev</varname> output is added if it exists, otherwise the first output is added. In addition to that, <varname>propagatedBuildOutputs</varname> of that package which by default contain <varname>$outputBin</varname> and <varname>$outputLib</varname> are also added. (See <xref linkend="multiple-output-file-type-groups" />.)</para>
</section>
<para>
In the Nix language the individual outputs can be reached explicitly as
attributes, e.g. <varname>coreutils.info</varname>, but the typical case is
just using packages as build inputs.
</para>
<para>
When a multiple-output derivation gets into a build input of another
derivation, the <varname>dev</varname> output is added if it exists,
otherwise the first output is added. In addition to that,
<varname>propagatedBuildOutputs</varname> of that package which by default
contain <varname>$outputBin</varname> and <varname>$outputLib</varname> are
also added. (See <xref linkend="multiple-output-file-type-groups" />.)
</para>
</section>
<section>
<title>Writing a split derivation</title>
<section><title>Writing a split derivation</title>
<para>Here you find how to write a derivation that produces multiple outputs.</para>
<para>In nixpkgs there is a framework supporting multiple-output derivations. It tries to cover most cases by default behavior. You can find the source separated in &lt;<filename>nixpkgs/pkgs/build-support/setup-hooks/multiple-outputs.sh</filename>&gt;; it's relatively well-readable. The whole machinery is triggered by defining the <varname>outputs</varname> attribute to contain the list of desired output names (strings).</para>
<programlisting>outputs = [ "bin" "dev" "out" "doc" ];</programlisting>
<para>Often such a single line is enough. For each output an equally named environment variable is passed to the builder and contains the path in nix store for that output. Typically you also want to have the main <varname>out</varname> output, as it catches any files that didn't get elsewhere.</para>
<note><para>There is a special handling of the <varname>debug</varname> output, described at <xref linkend="stdenv-separateDebugInfo" />.</para></note>
<para>
Here you find how to write a derivation that produces multiple outputs.
</para>
<para>
In nixpkgs there is a framework supporting multiple-output derivations. It
tries to cover most cases by default behavior. You can find the source
separated in
&lt;<filename>nixpkgs/pkgs/build-support/setup-hooks/multiple-outputs.sh</filename>&gt;;
it's relatively well-readable. The whole machinery is triggered by defining
the <varname>outputs</varname> attribute to contain the list of desired
output names (strings).
</para>
<programlisting>outputs = [ "bin" "dev" "out" "doc" ];</programlisting>
<para>
Often such a single line is enough. For each output an equally named
environment variable is passed to the builder and contains the path in nix
store for that output. Typically you also want to have the main
<varname>out</varname> output, as it catches any files that didn't get
elsewhere.
</para>
<note>
<para>
There is a special handling of the <varname>debug</varname> output,
described at <xref linkend="stdenv-separateDebugInfo" />.
</para>
</note>
<section xml:id="multiple-output-file-binaries-first-convention">
<title><quote>Binaries first</quote></title>
<para>A commonly adopted convention in <literal>nixpkgs</literal> is that executables provided by the package are contained within its first output. This convention allows the dependent packages to reference the executables provided by packages in a uniform manner. For instance, provided with the knowledge that the <literal>perl</literal> package contains a <literal>perl</literal> executable it can be referenced as <literal>${pkgs.perl}/bin/perl</literal> within a Nix derivation that needs to execute a Perl script.</para>
<para>The <literal>glibc</literal> package is a deliberate single exception to the <quote>binaries first</quote> convention. The <literal>glibc</literal> has <literal>libs</literal> as its first output allowing the libraries provided by <literal>glibc</literal> to be referenced directly (e.g. <literal>${stdenv.glibc}/lib/ld-linux-x86-64.so.2</literal>). The executables provided by <literal>glibc</literal> can be accessed via its <literal>bin</literal> attribute (e.g. <literal>${stdenv.glibc.bin}/bin/ldd</literal>).</para>
<para>The reason for why <literal>glibc</literal> deviates from the convention is because referencing a library provided by <literal>glibc</literal> is a very common operation among Nix packages. For instance, third-party executables packaged by Nix are typically patched and relinked with the relevant version of <literal>glibc</literal> libraries from Nix packages (please see the documentation on <link xlink:href="https://nixos.org/patchelf.html">patchelf</link> for more details).</para>
<title><quote>Binaries first</quote></title>
<para>
A commonly adopted convention in <literal>nixpkgs</literal> is that
executables provided by the package are contained within its first output.
This convention allows the dependent packages to reference the executables
provided by packages in a uniform manner. For instance, provided with the
knowledge that the <literal>perl</literal> package contains a
<literal>perl</literal> executable it can be referenced as
<literal>${pkgs.perl}/bin/perl</literal> within a Nix derivation that needs
to execute a Perl script.
</para>
<para>
The <literal>glibc</literal> package is a deliberate single exception to
the <quote>binaries first</quote> convention. The <literal>glibc</literal>
has <literal>libs</literal> as its first output allowing the libraries
provided by <literal>glibc</literal> to be referenced directly (e.g.
<literal>${stdenv.glibc}/lib/ld-linux-x86-64.so.2</literal>). The
executables provided by <literal>glibc</literal> can be accessed via its
<literal>bin</literal> attribute (e.g.
<literal>${stdenv.glibc.bin}/bin/ldd</literal>).
</para>
<para>
The reason for why <literal>glibc</literal> deviates from the convention is
because referencing a library provided by <literal>glibc</literal> is a
very common operation among Nix packages. For instance, third-party
executables packaged by Nix are typically patched and relinked with the
relevant version of <literal>glibc</literal> libraries from Nix packages
(please see the documentation on
<link xlink:href="https://nixos.org/patchelf.html">patchelf</link> for more
details).
</para>
</section>
<section xml:id="multiple-output-file-type-groups">
<title>File type groups</title>
<para>The support code currently recognizes some particular kinds of outputs and either instructs the build system of the package to put files into their desired outputs or it moves the files during the fixup phase. Each group of file types has an <varname>outputFoo</varname> variable specifying the output name where they should go. If that variable isn't defined by the derivation writer, it is guessed &ndash; a default output name is defined, falling back to other possibilities if the output isn't defined.</para>
<variablelist>
<title>File type groups</title>
<varlistentry><term><varname>
$outputDev</varname></term><listitem><para>
is for development-only files. These include C(++) headers, pkg-config, cmake and aclocal files. They go to <varname>dev</varname> or <varname>out</varname> by default.
</para></listitem>
</varlistentry>
<para>
The support code currently recognizes some particular kinds of outputs and
either instructs the build system of the package to put files into their
desired outputs or it moves the files during the fixup phase. Each group of
file types has an <varname>outputFoo</varname> variable specifying the
output name where they should go. If that variable isn't defined by the
derivation writer, it is guessed &ndash; a default output name is defined,
falling back to other possibilities if the output isn't defined.
</para>
<varlistentry><term><varname>
$outputBin</varname></term><listitem><para>
is meant for user-facing binaries, typically residing in bin/. They go to <varname>bin</varname> or <varname>out</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputLib</varname></term><listitem><para>
is meant for libraries, typically residing in <filename>lib/</filename> and <filename>libexec/</filename>. They go to <varname>lib</varname> or <varname>out</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputDoc</varname></term><listitem><para>
is for user documentation, typically residing in <filename>share/doc/</filename>. It goes to <varname>doc</varname> or <varname>out</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputDevdoc</varname></term><listitem><para>
is for <emphasis>developer</emphasis> documentation. Currently we count gtk-doc and devhelp books in there. It goes to <varname>devdoc</varname> or is removed (!) by default. This is because e.g. gtk-doc tends to be rather large and completely unused by nixpkgs users.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputMan</varname></term><listitem><para>
is for man pages (except for section 3). They go to <varname>man</varname> or <varname>$outputBin</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputDevman</varname></term><listitem><para>
is for section 3 man pages. They go to <varname>devman</varname> or <varname>$outputMan</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputInfo</varname></term><listitem><para>
is for info pages. They go to <varname>info</varname> or <varname>$outputBin</varname> by default.
</para></listitem></varlistentry>
</variablelist>
<variablelist>
<varlistentry>
<term><varname>
$outputDev</varname>
</term>
<listitem>
<para>
is for development-only files. These include C(++) headers, pkg-config,
cmake and aclocal files. They go to <varname>dev</varname> or
<varname>out</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputBin</varname>
</term>
<listitem>
<para>
is meant for user-facing binaries, typically residing in bin/. They go
to <varname>bin</varname> or <varname>out</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputLib</varname>
</term>
<listitem>
<para>
is meant for libraries, typically residing in <filename>lib/</filename>
and <filename>libexec/</filename>. They go to <varname>lib</varname> or
<varname>out</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputDoc</varname>
</term>
<listitem>
<para>
is for user documentation, typically residing in
<filename>share/doc/</filename>. It goes to <varname>doc</varname> or
<varname>out</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputDevdoc</varname>
</term>
<listitem>
<para>
is for <emphasis>developer</emphasis> documentation. Currently we count
gtk-doc and devhelp books in there. It goes to <varname>devdoc</varname>
or is removed (!) by default. This is because e.g. gtk-doc tends to be
rather large and completely unused by nixpkgs users.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputMan</varname>
</term>
<listitem>
<para>
is for man pages (except for section 3). They go to
<varname>man</varname> or <varname>$outputBin</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputDevman</varname>
</term>
<listitem>
<para>
is for section 3 man pages. They go to <varname>devman</varname> or
<varname>$outputMan</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputInfo</varname>
</term>
<listitem>
<para>
is for info pages. They go to <varname>info</varname> or
<varname>$outputBin</varname> by default.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section><title>Common caveats</title>
<itemizedlist>
<listitem><para>Some configure scripts don't like some of the parameters passed by default by the framework, e.g. <literal>--docdir=/foo/bar</literal>. You can disable this by setting <literal>setOutputFlags = false;</literal>.</para></listitem>
<listitem><para>The outputs of a single derivation can retain references to each other, but note that circular references are not allowed. (And each strongly-connected component would act as a single output anyway.)</para></listitem>
<listitem><para>Most of split packages contain their core functionality in libraries. These libraries tend to refer to various kind of data that typically gets into <varname>out</varname>, e.g. locale strings, so there is often no advantage in separating the libraries into <varname>lib</varname>, as keeping them in <varname>out</varname> is easier.</para></listitem>
<listitem><para>Some packages have hidden assumptions on install paths, which complicates splitting.</para></listitem>
</itemizedlist>
<section>
<title>Common caveats</title>
<itemizedlist>
<listitem>
<para>
Some configure scripts don't like some of the parameters passed by
default by the framework, e.g. <literal>--docdir=/foo/bar</literal>. You
can disable this by setting <literal>setOutputFlags = false;</literal>.
</para>
</listitem>
<listitem>
<para>
The outputs of a single derivation can retain references to each other,
but note that circular references are not allowed. (And each
strongly-connected component would act as a single output anyway.)
</para>
</listitem>
<listitem>
<para>
Most of split packages contain their core functionality in libraries.
These libraries tend to refer to various kind of data that typically gets
into <varname>out</varname>, e.g. locale strings, so there is often no
advantage in separating the libraries into <varname>lib</varname>, as
keeping them in <varname>out</varname> is easier.
</para>
</listitem>
<listitem>
<para>
Some packages have hidden assumptions on install paths, which complicates
splitting.
</para>
</listitem>
</itemizedlist>
</section>
</section><!--Writing a split derivation-->
</section>
<!--Writing a split derivation-->
</chapter>

240
doc/overlays.xml
View File

@ -1,95 +1,117 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-overlays">
<title>Overlays</title>
<para>This chapter describes how to extend and change Nixpkgs packages using
overlays. Overlays are used to add layers in the fix-point used by Nixpkgs
to compose the set of all packages.</para>
<para>Nixpkgs can be configured with a list of overlays, which are
applied in order. This means that the order of the overlays can be significant
if multiple layers override the same package.</para>
<title>Overlays</title>
<para>
This chapter describes how to extend and change Nixpkgs packages using
overlays. Overlays are used to add layers in the fix-point used by Nixpkgs to
compose the set of all packages.
</para>
<para>
Nixpkgs can be configured with a list of overlays, which are applied in
order. This means that the order of the overlays can be significant if
multiple layers override the same package.
</para>
<!--============================================================-->
<section xml:id="sec-overlays-install">
<title>Installing overlays</title>
<section xml:id="sec-overlays-install">
<title>Installing overlays</title>
<para>
The list of overlays is determined as follows.
</para>
<para>The list of overlays is determined as follows.</para>
<para>
If the <varname>overlays</varname> argument is not provided explicitly, we
look for overlays in a path. The path is determined as follows:
<orderedlist>
<listitem>
<para>
First, if an <varname>overlays</varname> argument to the nixpkgs function
itself is given, then that is used.
</para>
<para>
This can be passed explicitly when importing nipxkgs, for example
<literal>import &lt;nixpkgs> { overlays = [ overlay1 overlay2 ];
}</literal>.
</para>
</listitem>
<listitem>
<para>
Otherwise, if the Nix path entry <literal>&lt;nixpkgs-overlays></literal>
exists, we look for overlays at that path, as described below.
</para>
<para>
See the section on <literal>NIX_PATH</literal> in the Nix manual for more
details on how to set a value for
<literal>&lt;nixpkgs-overlays>.</literal>
</para>
</listitem>
<listitem>
<para>
If one of <filename>~/.config/nixpkgs/overlays.nix</filename> and
<filename>~/.config/nixpkgs/overlays/</filename> exists, then we look for
overlays at that path, as described below. It is an error if both exist.
</para>
</listitem>
</orderedlist>
</para>
<para>If the <varname>overlays</varname> argument is not provided explicitly, we look for overlays in a path. The path
is determined as follows:
<para>
If we are looking for overlays at a path, then there are two cases:
<itemizedlist>
<listitem>
<para>
If the path is a file, then the file is imported as a Nix expression and
used as the list of overlays.
</para>
</listitem>
<listitem>
<para>
If the path is a directory, then we take the content of the directory,
order it lexicographically, and attempt to interpret each as an overlay
by:
<itemizedlist>
<listitem>
<para>
Importing the file, if it is a <literal>.nix</literal> file.
</para>
</listitem>
<listitem>
<para>
Importing a top-level <filename>default.nix</filename> file, if it is
a directory.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
<orderedlist>
<listitem>
<para>First, if an <varname>overlays</varname> argument to the nixpkgs function itself is given,
then that is used.</para>
<para>This can be passed explicitly when importing nipxkgs, for example
<literal>import &lt;nixpkgs> { overlays = [ overlay1 overlay2 ]; }</literal>.</para>
</listitem>
<listitem>
<para>Otherwise, if the Nix path entry <literal>&lt;nixpkgs-overlays></literal> exists, we look for overlays
at that path, as described below.</para>
<para>See the section on <literal>NIX_PATH</literal> in the Nix manual for more details on how to
set a value for <literal>&lt;nixpkgs-overlays>.</literal></para>
</listitem>
<listitem>
<para>If one of <filename>~/.config/nixpkgs/overlays.nix</filename> and
<filename>~/.config/nixpkgs/overlays/</filename> exists, then we look for overlays at that path, as
described below. It is an error if both exist.</para>
</listitem>
</orderedlist>
</para>
<para>If we are looking for overlays at a path, then there are two cases:
<itemizedlist>
<listitem>
<para>If the path is a file, then the file is imported as a Nix expression and used as the list of
overlays.</para>
</listitem>
<listitem>
<para>If the path is a directory, then we take the content of the directory, order it
lexicographically, and attempt to interpret each as an overlay by:
<itemizedlist>
<listitem>
<para>Importing the file, if it is a <literal>.nix</literal> file.</para>
</listitem>
<listitem>
<para>Importing a top-level <filename>default.nix</filename> file, if it is a directory.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
<para>On a NixOS system the value of the <literal>nixpkgs.overlays</literal> option, if present,
is passed to the system Nixpkgs directly as an argument. Note that this does not affect the overlays for
non-NixOS operations (e.g. <literal>nix-env</literal>), which are looked up independently.</para>
<para>The <filename>overlays.nix</filename> option therefore provides a convenient way to use the same
overlays for a NixOS system configuration and user configuration: the same file can be used
as <filename>overlays.nix</filename> and imported as the value of <literal>nixpkgs.overlays</literal>.</para>
</section>
<para>
On a NixOS system the value of the <literal>nixpkgs.overlays</literal>
option, if present, is passed to the system Nixpkgs directly as an argument.
Note that this does not affect the overlays for non-NixOS operations (e.g.
<literal>nix-env</literal>), which are looked up independently.
</para>
<para>
The <filename>overlays.nix</filename> option therefore provides a convenient
way to use the same overlays for a NixOS system configuration and user
configuration: the same file can be used as
<filename>overlays.nix</filename> and imported as the value of
<literal>nixpkgs.overlays</literal>.
</para>
</section>
<!--============================================================-->
<section xml:id="sec-overlays-definition">
<title>Defining overlays</title>
<section xml:id="sec-overlays-definition">
<title>Defining overlays</title>
<para>Overlays are Nix functions which accept two arguments,
conventionally called <varname>self</varname> and <varname>super</varname>,
and return a set of packages. For example, the following is a valid overlay.</para>
<para>
Overlays are Nix functions which accept two arguments, conventionally called
<varname>self</varname> and <varname>super</varname>, and return a set of
packages. For example, the following is a valid overlay.
</para>
<programlisting>
self: super:
@ -104,31 +126,39 @@ self: super:
}
</programlisting>
<para>The first argument (<varname>self</varname>) corresponds to the final package
set. You should use this set for the dependencies of all packages specified in your
overlay. For example, all the dependencies of <varname>rr</varname> in the example above come
from <varname>self</varname>, as well as the overridden dependencies used in the
<varname>boost</varname> override.</para>
<para>
The first argument (<varname>self</varname>) corresponds to the final
package set. You should use this set for the dependencies of all packages
specified in your overlay. For example, all the dependencies of
<varname>rr</varname> in the example above come from
<varname>self</varname>, as well as the overridden dependencies used in the
<varname>boost</varname> override.
</para>
<para>The second argument (<varname>super</varname>)
corresponds to the result of the evaluation of the previous stages of
Nixpkgs. It does not contain any of the packages added by the current
overlay, nor any of the following overlays. This set should be used either
to refer to packages you wish to override, or to access functions defined
in Nixpkgs. For example, the original recipe of <varname>boost</varname>
in the above example, comes from <varname>super</varname>, as well as the
<varname>callPackage</varname> function.</para>
<para>
The second argument (<varname>super</varname>) corresponds to the result of
the evaluation of the previous stages of Nixpkgs. It does not contain any of
the packages added by the current overlay, nor any of the following
overlays. This set should be used either to refer to packages you wish to
override, or to access functions defined in Nixpkgs. For example, the
original recipe of <varname>boost</varname> in the above example, comes from
<varname>super</varname>, as well as the <varname>callPackage</varname>
function.
</para>
<para>The value returned by this function should be a set similar to
<filename>pkgs/top-level/all-packages.nix</filename>, containing
overridden and/or new packages.</para>
<para>Overlays are similar to other methods for customizing Nixpkgs, in particular
the <literal>packageOverrides</literal> attribute described in <xref linkend="sec-modify-via-packageOverrides"/>.
Indeed, <literal>packageOverrides</literal> acts as an overlay with only the
<varname>super</varname> argument. It is therefore appropriate for basic use,
but overlays are more powerful and easier to distribute.</para>
</section>
<para>
The value returned by this function should be a set similar to
<filename>pkgs/top-level/all-packages.nix</filename>, containing overridden
and/or new packages.
</para>
<para>
Overlays are similar to other methods for customizing Nixpkgs, in particular
the <literal>packageOverrides</literal> attribute described in
<xref linkend="sec-modify-via-packageOverrides"/>. Indeed,
<literal>packageOverrides</literal> acts as an overlay with only the
<varname>super</varname> argument. It is therefore appropriate for basic
use, but overlays are more powerful and easier to distribute.
</para>
</section>
</chapter>

901
doc/package-notes.xml
View File

File diff suppressed because it is too large Load Diff

84
doc/platform-notes.xml
View File

@ -1,27 +1,25 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-platform-nodes">
<title>Platform Notes</title>
<section xml:id="sec-darwin">
<title>Darwin (macOS)</title>
<title>Platform Notes</title>
<para>
Some common issues when packaging software for darwin:
</para>
<section xml:id="sec-darwin">
<title>Darwin (macOS)</title>
<para>Some common issues when packaging software for darwin:</para>
<itemizedlist>
<listitem>
<itemizedlist>
<listitem>
<para>
The darwin <literal>stdenv</literal> uses clang instead of gcc.
When referring to the compiler <varname>$CC</varname> or <command>cc</command>
will work in both cases. Some builds hardcode gcc/g++ in their
build scripts, that can usually be fixed with using something
like <literal>makeFlags = [ "CC=cc" ];</literal> or by patching
the build scripts.
The darwin <literal>stdenv</literal> uses clang instead of gcc. When
referring to the compiler <varname>$CC</varname> or <command>cc</command>
will work in both cases. Some builds hardcode gcc/g++ in their build
scripts, that can usually be fixed with using something like
<literal>makeFlags = [ "CC=cc" ];</literal> or by patching the build
scripts.
</para>
<programlisting>
<programlisting>
stdenv.mkDerivation {
name = "libfoo-1.2.3";
# ...
@ -30,36 +28,33 @@
'';
}
</programlisting>
</listitem>
<listitem>
</listitem>
<listitem>
<para>
On darwin libraries are linked using absolute paths, libraries
are resolved by their <literal>install_name</literal> at link
time. Sometimes packages won't set this correctly causing the
library lookups to fail at runtime. This can be fixed by adding
extra linker flags or by running <command>install_name_tool -id</command>
during the <function>fixupPhase</function>.
On darwin libraries are linked using absolute paths, libraries are
resolved by their <literal>install_name</literal> at link time. Sometimes
packages won't set this correctly causing the library lookups to fail at
runtime. This can be fixed by adding extra linker flags or by running
<command>install_name_tool -id</command> during the
<function>fixupPhase</function>.
</para>
<programlisting>
<programlisting>
stdenv.mkDerivation {
name = "libfoo-1.2.3";
# ...
makeFlags = stdenv.lib.optional stdenv.isDarwin "LDFLAGS=-Wl,-install_name,$(out)/lib/libfoo.dylib";
}
</programlisting>
</listitem>
<listitem>
</listitem>
<listitem>
<para>
Some packages assume xcode is available and use <command>xcrun</command>
to resolve build tools like <command>clang</command>, etc.
This causes errors like <code>xcode-select: error: no developer tools were found at '/Applications/Xcode.app'</code>
while the build doesn't actually depend on xcode.
Some packages assume xcode is available and use <command>xcrun</command>
to resolve build tools like <command>clang</command>, etc. This causes
errors like <code>xcode-select: error: no developer tools were found at
'/Applications/Xcode.app'</code> while the build doesn't actually depend
on xcode.
</para>
<programlisting>
<programlisting>
stdenv.mkDerivation {
name = "libfoo-1.2.3";
# ...
@ -69,15 +64,12 @@
'';
}
</programlisting>
<para>
The package <literal>xcbuild</literal> can be used to build projects
that really depend on Xcode, however projects that build some kind of
graphical interface won't work without using Xcode in an impure way.
The package <literal>xcbuild</literal> can be used to build projects that
really depend on Xcode, however projects that build some kind of graphical
interface won't work without using Xcode in an impure way.
</para>
</listitem>
</itemizedlist>
</section>
</listitem>
</itemizedlist>
</section>
</chapter>

374
doc/quick-start.xml
View File

@ -1,223 +1,219 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-quick-start">
<title>Quick Start to Adding a Package</title>
<para>To add a package to Nixpkgs:
<orderedlist>
<listitem>
<para>Checkout the Nixpkgs source tree:
<title>Quick Start to Adding a Package</title>
<para>
To add a package to Nixpkgs:
<orderedlist>
<listitem>
<para>
Checkout the Nixpkgs source tree:
<screen>
$ git clone git://github.com/NixOS/nixpkgs.git
$ cd nixpkgs</screen>
</para>
</listitem>
<listitem>
<para>Find a good place in the Nixpkgs tree to add the Nix
expression for your package. For instance, a library package
typically goes into
<filename>pkgs/development/libraries/<replaceable>pkgname</replaceable></filename>,
while a web browser goes into
<filename>pkgs/applications/networking/browsers/<replaceable>pkgname</replaceable></filename>.
See <xref linkend="sec-organisation" /> for some hints on the tree
organisation. Create a directory for your package, e.g.
</listitem>
<listitem>
<para>
Find a good place in the Nixpkgs tree to add the Nix expression for your
package. For instance, a library package typically goes into
<filename>pkgs/development/libraries/<replaceable>pkgname</replaceable></filename>,
while a web browser goes into
<filename>pkgs/applications/networking/browsers/<replaceable>pkgname</replaceable></filename>.
See <xref linkend="sec-organisation" /> for some hints on the tree
organisation. Create a directory for your package, e.g.
<screen>
$ mkdir pkgs/development/libraries/libfoo</screen>
</para>
</listitem>
<listitem>
<para>In the package directory, create a Nix expression — a piece
of code that describes how to build the package. In this case, it
should be a <emphasis>function</emphasis> that is called with the
package dependencies as arguments, and returns a build of the
package in the Nix store. The expression should usually be called
<filename>default.nix</filename>.
</listitem>
<listitem>
<para>
In the package directory, create a Nix expression — a piece of code that
describes how to build the package. In this case, it should be a
<emphasis>function</emphasis> that is called with the package dependencies
as arguments, and returns a build of the package in the Nix store. The
expression should usually be called <filename>default.nix</filename>.
<screen>
$ emacs pkgs/development/libraries/libfoo/default.nix
$ git add pkgs/development/libraries/libfoo/default.nix</screen>
</para>
<para>You can have a look at the existing Nix expressions under
<filename>pkgs/</filename> to see how it’s done. Here are some
good ones:
<itemizedlist>
<listitem>
<para>GNU Hello: <link
<para>
You can have a look at the existing Nix expressions under
<filename>pkgs/</filename> to see how it’s done. Here are some good
ones:
<itemizedlist>
<listitem>
<para>
GNU Hello:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/hello/default.nix"><filename>pkgs/applications/misc/hello/default.nix</filename></link>.
Trivial package, which specifies some <varname>meta</varname>
attributes which is good practice.</para>
</listitem>
<listitem>
<para>GNU cpio: <link
Trivial package, which specifies some <varname>meta</varname>
attributes which is good practice.
</para>
</listitem>
<listitem>
<para>
GNU cpio:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/archivers/cpio/default.nix"><filename>pkgs/tools/archivers/cpio/default.nix</filename></link>.
Also a simple package. The generic builder in
<varname>stdenv</varname> does everything for you. It has
no dependencies beyond <varname>stdenv</varname>.</para>
</listitem>
<listitem>
<para>GNU Multiple Precision arithmetic library (GMP): <link
Also a simple package. The generic builder in <varname>stdenv</varname>
does everything for you. It has no dependencies beyond
<varname>stdenv</varname>.
</para>
</listitem>
<listitem>
<para>
GNU Multiple Precision arithmetic library (GMP):
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/libraries/gmp/5.1.x.nix"><filename>pkgs/development/libraries/gmp/5.1.x.nix</filename></link>.
Also done by the generic builder, but has a dependency on
<varname>m4</varname>.</para>
</listitem>
<listitem>
<para>Pan, a GTK-based newsreader: <link
Also done by the generic builder, but has a dependency on
<varname>m4</varname>.
</para>
</listitem>
<listitem>
<para>
Pan, a GTK-based newsreader:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/newsreaders/pan/default.nix"><filename>pkgs/applications/networking/newsreaders/pan/default.nix</filename></link>.
Has an optional dependency on <varname>gtkspell</varname>,
which is only built if <varname>spellCheck</varname> is
<literal>true</literal>.</para>
</listitem>
<listitem>
<para>Apache HTTPD: <link
Has an optional dependency on <varname>gtkspell</varname>, which is
only built if <varname>spellCheck</varname> is <literal>true</literal>.
</para>
</listitem>
<listitem>
<para>
Apache HTTPD:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/http/apache-httpd/2.4.nix"><filename>pkgs/servers/http/apache-httpd/2.4.nix</filename></link>.
A bunch of optional features, variable substitutions in the
configure flags, a post-install hook, and miscellaneous
hackery.</para>
</listitem>
<listitem>
<para>Thunderbird: <link
A bunch of optional features, variable substitutions in the configure
flags, a post-install hook, and miscellaneous hackery.
</para>
</listitem>
<listitem>
<para>
Thunderbird:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/mailreaders/thunderbird/default.nix"><filename>pkgs/applications/networking/mailreaders/thunderbird/default.nix</filename></link>.
Lots of dependencies.</para>
</listitem>
<listitem>
<para>JDiskReport, a Java utility: <link
Lots of dependencies.
</para>
</listitem>
<listitem>
<para>
JDiskReport, a Java utility:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/jdiskreport/default.nix"><filename>pkgs/tools/misc/jdiskreport/default.nix</filename></link>
(and the <link
(and the
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/jdiskreport/builder.sh">builder</link>).
Nixpkgs doesn’t have a decent <varname>stdenv</varname> for
Java yet so this is pretty ad-hoc.</para>
</listitem>
<listitem>
<para>XML::Simple, a Perl module: <link
Nixpkgs doesn’t have a decent <varname>stdenv</varname> for Java yet
so this is pretty ad-hoc.
</para>
</listitem>
<listitem>
<para>
XML::Simple, a Perl module:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link>
(search for the <varname>XMLSimple</varname> attribute).
Most Perl modules are so simple to build that they are
defined directly in <filename>perl-packages.nix</filename>;
no need to make a separate file for them.</para>
</listitem>
<listitem>
<para>Adobe Reader: <link
(search for the <varname>XMLSimple</varname> attribute). Most Perl
modules are so simple to build that they are defined directly in
<filename>perl-packages.nix</filename>; no need to make a separate file
for them.
</para>
</listitem>
<listitem>
<para>
Adobe Reader:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/adobe-reader/default.nix"><filename>pkgs/applications/misc/adobe-reader/default.nix</filename></link>.
Shows how binary-only packages can be supported. In
particular the <link
Shows how binary-only packages can be supported. In particular the
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/adobe-reader/builder.sh">builder</link>
uses <command>patchelf</command> to set the RUNPATH and ELF
interpreter of the executables so that the right libraries
are found at runtime.</para>
</listitem>
</itemizedlist>
uses <command>patchelf</command> to set the RUNPATH and ELF interpreter
of the executables so that the right libraries are found at runtime.
</para>
</listitem>
</itemizedlist>
</para>
<para>Some notes:
<itemizedlist>
<listitem>
<para>All <varname linkend="chap-meta">meta</varname>
attributes are optional, but it’s still a good idea to
provide at least the <varname>description</varname>,
<varname>homepage</varname> and <varname
linkend="sec-meta-license">license</varname>.</para>
</listitem>
<listitem>
<para>You can use <command>nix-prefetch-url</command> (or similar nix-prefetch-git, etc)
<replaceable>url</replaceable> to get the SHA-256 hash of
source distributions. There are similar commands as <command>nix-prefetch-git</command> and
<command>nix-prefetch-hg</command> available in <literal>nix-prefetch-scripts</literal> package.</para>
</listitem>
<listitem>
<para>A list of schemes for <literal>mirror://</literal>
URLs can be found in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/fetchurl/mirrors.nix"><filename>pkgs/build-support/fetchurl/mirrors.nix</filename></link>.</para>
</listitem>
</itemizedlist>
<para>
Some notes:
<itemizedlist>
<listitem>
<para>
All <varname linkend="chap-meta">meta</varname> attributes are
optional, but it’s still a good idea to provide at least the
<varname>description</varname>, <varname>homepage</varname> and
<varname
linkend="sec-meta-license">license</varname>.
</para>
</listitem>
<listitem>
<para>
You can use <command>nix-prefetch-url</command> (or similar
nix-prefetch-git, etc) <replaceable>url</replaceable> to get the
SHA-256 hash of source distributions. There are similar commands as
<command>nix-prefetch-git</command> and
<command>nix-prefetch-hg</command> available in
<literal>nix-prefetch-scripts</literal> package.
</para>
</listitem>
<listitem>
<para>
A list of schemes for <literal>mirror://</literal> URLs can be found in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/fetchurl/mirrors.nix"><filename>pkgs/build-support/fetchurl/mirrors.nix</filename></link>.
</para>
</listitem>
</itemizedlist>
</para>
<para>The exact syntax and semantics of the Nix expression
language, including the built-in function, are described in the
Nix manual in the <link
<para>
The exact syntax and semantics of the Nix expression language, including
the built-in function, are described in the Nix manual in the
<link
xlink:href="http://hydra.nixos.org/job/nix/trunk/tarball/latest/download-by-type/doc/manual/#chap-writing-nix-expressions">chapter
on writing Nix expressions</link>.</para>
</listitem>
<listitem>
<para>Add a call to the function defined in the previous step to
<link
on writing Nix expressions</link>.
</para>
</listitem>
<listitem>
<para>
Add a call to the function defined in the previous step to
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/all-packages.nix"><filename>pkgs/top-level/all-packages.nix</filename></link>
with some descriptive name for the variable,
e.g. <varname>libfoo</varname>.
<screen>
with some descriptive name for the variable, e.g.
<varname>libfoo</varname>.
<screen>
$ emacs pkgs/top-level/all-packages.nix</screen>
</para>
<para>The attributes in that file are sorted by category (like
“Development / Libraries”) that more-or-less correspond to the
directory structure of Nixpkgs, and then by attribute name.</para>
</listitem>
<listitem>
<para>To test whether the package builds, run the following command
from the root of the nixpkgs source tree:
<screen>
<para>
The attributes in that file are sorted by category (like “Development /
Libraries”) that more-or-less correspond to the directory structure of
Nixpkgs, and then by attribute name.
</para>
</listitem>
<listitem>
<para>
To test whether the package builds, run the following command from the
root of the nixpkgs source tree:
<screen>
$ nix-build -A libfoo</screen>
where <varname>libfoo</varname> should be the variable name
defined in the previous step. You may want to add the flag
<option>-K</option> to keep the temporary build directory in case
something fails. If the build succeeds, a symlink
<filename>./result</filename> to the package in the Nix store is
created.</para>
</listitem>
<listitem>
<para>If you want to install the package into your profile
(optional), do
<screen>
$ nix-env -f . -iA libfoo</screen>
where <varname>libfoo</varname> should be the variable name defined in the
previous step. You may want to add the flag <option>-K</option> to keep
the temporary build directory in case something fails. If the build
succeeds, a symlink <filename>./result</filename> to the package in the
Nix store is created.
</para>
</listitem>
<listitem>
<para>Optionally commit the new package and open a pull request, or send a patch to
<literal>https://groups.google.com/forum/#!forum/nix-devel</literal>.</para>
</listitem>
</orderedlist>
</para>
</listitem>
<listitem>
<para>
If you want to install the package into your profile (optional), do
<screen>
$ nix-env -f . -iA libfoo</screen>
</para>
</listitem>
<listitem>
<para>
Optionally commit the new package and open a pull request, or send a patch
to <literal>https://groups.google.com/forum/#!forum/nix-devel</literal>.
</para>
</listitem>
</orderedlist>
</para>
</chapter>

1341
doc/release-notes.xml
View File

File diff suppressed because it is too large Load Diff

715
doc/reviewing-contributions.xml
View File

@ -3,95 +3,148 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-reviewing-contributions">
<title>Reviewing contributions</title>
<warning>
<para>The following section is a draft and reviewing policy is still being
discussed.</para>
</warning>
<para>The nixpkgs projects receives a fairly high number of contributions via
GitHub pull-requests. Reviewing and approving these is an important task and a
way to contribute to the project.</para>
<para>The high change rate of nixpkgs make any pull request that is open for
long enough subject to conflicts that will require extra work from the
submitter or the merger. Reviewing pull requests in a timely manner and being
<title>Reviewing contributions</title>
<warning>
<para>
The following section is a draft and reviewing policy is still being
discussed.
</para>
</warning>
<para>
The nixpkgs projects receives a fairly high number of contributions via
GitHub pull-requests. Reviewing and approving these is an important task and
a way to contribute to the project.
</para>
<para>
The high change rate of nixpkgs make any pull request that is open for long
enough subject to conflicts that will require extra work from the submitter
or the merger. Reviewing pull requests in a timely manner and being
responsive to the comments is the key to avoid these. GitHub provides sort
filters that can be used to see the <link
filters that can be used to see the
<link
xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-desc">most
recently</link> and the <link
recently</link> and the
<link
xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-asc">least
recently</link> updated pull-requests.
We highly encourage looking at <link xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+review%3Anone+status%3Asuccess+-label%3A%222.status%3A+work-in-progress%22+no%3Aproject+no%3Aassignee+no%3Amilestone">
this list of ready to merge, unreviewed pull requests</link>.</para>
<para>When reviewing a pull request, please always be nice and polite.
recently</link> updated pull-requests. We highly encourage looking at
<link xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+review%3Anone+status%3Asuccess+-label%3A%222.status%3A+work-in-progress%22+no%3Aproject+no%3Aassignee+no%3Amilestone">
this list of ready to merge, unreviewed pull requests</link>.
</para>
<para>
When reviewing a pull request, please always be nice and polite.
Controversial changes can lead to controversial opinions, but it is important
to respect every community members and their work.</para>
<para>GitHub provides reactions, they are a simple and quick way to provide
to respect every community members and their work.
</para>
<para>
GitHub provides reactions, they are a simple and quick way to provide
feedback to pull-requests or any comments. The thumb-down reaction should be
used with care and if possible accompanied with some explanations so the
submitter has directions to improve his contribution.</para>
<para>Pull-requests reviews should include a list of what has been reviewed in a
comment, so other reviewers and mergers can know the state of the
review.</para>
<para>All the review template samples provided in this section are generic and
submitter has directions to improve his contribution.
</para>
<para>
Pull-requests reviews should include a list of what has been reviewed in a
comment, so other reviewers and mergers can know the state of the review.
</para>
<para>
All the review template samples provided in this section are generic and
meant as examples. Their usage is optional and the reviewer is free to adapt
them to his liking.</para>
them to his liking.
</para>
<section>
<title>Package updates</title>
<section><title>Package updates</title>
<para>
A package update is the most trivial and common type of pull-request. These
pull-requests mainly consist in updating the version part of the package
name and the source hash.
</para>
<para>A package update is the most trivial and common type of pull-request.
These pull-requests mainly consist in updating the version part of the package
name and the source hash.</para>
<para>It can happen that non trivial updates include patches or more complex
changes.</para>
<para>
It can happen that non trivial updates include patches or more complex
changes.
</para>
<para>Reviewing process:</para>
<para>
Reviewing process:
</para>
<itemizedlist>
<listitem><para>Add labels to the pull-request. (Requires commit
rights)</para>
<itemizedlist>
<listitem>
<para>
Add labels to the pull-request. (Requires commit rights)
</para>
<itemizedlist>
<listitem><para><literal>8.has: package (update)</literal> and any topic
label that fit the updated package.</para></listitem>
<listitem>
<para>
<literal>8.has: package (update)</literal> and any topic label that fit
the updated package.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the package versioning is fitting the
guidelines.</para></listitem>
<listitem><para>Ensure that the commit text is fitting the
guidelines.</para></listitem>
<listitem><para>Ensure that the package maintainers are notified.</para>
</listitem>
<listitem>
<para>
Ensure that the package versioning is fitting the guidelines.
</para>
</listitem>
<listitem>
<para>
Ensure that the commit text is fitting the guidelines.
</para>
</listitem>
<listitem>
<para>
Ensure that the package maintainers are notified.
</para>
<itemizedlist>
<listitem><para>mention-bot usually notify GitHub users based on the
submitted changes, but it can happen that it misses some of the
package maintainers.</para></listitem>
<listitem>
<para>
mention-bot usually notify GitHub users based on the submitted changes,
but it can happen that it misses some of the package maintainers.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the meta field contains correct
information.</para>
</listitem>
<listitem>
<para>
Ensure that the meta field contains correct information.
</para>
<itemizedlist>
<listitem><para>License can change with version updates, so it should be
checked to be fitting upstream license.</para></listitem>
<listitem><para>If the package has no maintainer, a maintainer must be
set. This can be the update submitter or a community member that
accepts to take maintainership of the package.</para></listitem>
<listitem>
<para>
License can change with version updates, so it should be checked to be
fitting upstream license.
</para>
</listitem>
<listitem>
<para>
If the package has no maintainer, a maintainer must be set. This can be
the update submitter or a community member that accepts to take
maintainership of the package.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the code contains no typos.</para></listitem>
<listitem><para>Building the package locally.</para>
</listitem>
<listitem>
<para>
Ensure that the code contains no typos.
</para>
</listitem>
<listitem>
<para>
Building the package locally.
</para>
<itemizedlist>
<listitem><para>Pull-requests are often targeted to the master or staging
branch so building the pull-request locally as it is submitted can
trigger a large amount of source builds.</para>
<para>It is possible to rebase the changes on nixos-unstable or
nixpkgs-unstable for easier review by running the following commands
from a nixpkgs clone.
<listitem>
<para>
Pull-requests are often targeted to the master or staging branch so
building the pull-request locally as it is submitted can trigger a large
amount of source builds.
</para>
<para>
It is possible to rebase the changes on nixos-unstable or
nixpkgs-unstable for easier review by running the following commands
from a nixpkgs clone.
<screen>
$ git remote add channels https://github.com/NixOS/nixpkgs-channels.git <co
xml:id='reviewing-rebase-1' />
@ -100,43 +153,56 @@ $ git fetch origin pull/PRNUMBER/head <co xml:id='reviewing-rebase-3' />
$ git rebase --onto nixos-unstable BASEBRANCH FETCH_HEAD <co
xml:id='reviewing-rebase-4' />
</screen>
<calloutlist>
<callout arearefs='reviewing-rebase-1'>
<para>This should be done only once to be able to fetch channel
branches from the nixpkgs-channels repository.</para>
</callout>
<callout arearefs='reviewing-rebase-2'>
<para>Fetching the nixos-unstable branch.</para>
</callout>
<callout arearefs='reviewing-rebase-3'>
<para>Fetching the pull-request changes, <varname>PRNUMBER</varname>
is the number at the end of the pull-request title and
<varname>BASEBRANCH</varname> the base branch of the
pull-request.</para>
</callout>
<callout arearefs='reviewing-rebase-4'>
<para>Rebasing the pull-request changes to the nixos-unstable
branch.</para>
</callout>
</calloutlist>
</para>
</listitem>
<listitem>
<para>The <link xlink:href="https://github.com/madjar/nox">nox</link>
tool can be used to review a pull-request content in a single command.
It doesn't rebase on a channel branch so it might trigger multiple
source builds. <varname>PRNUMBER</varname> should be replaced by the
number at the end of the pull-request title.</para>
<calloutlist>
<callout arearefs='reviewing-rebase-1'>
<para>
This should be done only once to be able to fetch channel branches
from the nixpkgs-channels repository.
</para>
</callout>
<callout arearefs='reviewing-rebase-2'>
<para>
Fetching the nixos-unstable branch.
</para>
</callout>
<callout arearefs='reviewing-rebase-3'>
<para>
Fetching the pull-request changes, <varname>PRNUMBER</varname> is the
number at the end of the pull-request title and
<varname>BASEBRANCH</varname> the base branch of the pull-request.
</para>
</callout>
<callout arearefs='reviewing-rebase-4'>
<para>
Rebasing the pull-request changes to the nixos-unstable branch.
</para>
</callout>
</calloutlist>
</para>
</listitem>
<listitem>
<para>
The <link xlink:href="https://github.com/madjar/nox">nox</link> tool can
be used to review a pull-request content in a single command. It doesn't
rebase on a channel branch so it might trigger multiple source builds.
<varname>PRNUMBER</varname> should be replaced by the number at the end
of the pull-request title.
</para>
<screen>
$ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
</screen>
</listitem>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Running every binary.</para></listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Running every binary.
</para>
</listitem>
</itemizedlist>
<example><title>Sample template for a package update review</title>
<example>
<title>Sample template for a package update review</title>
<screen>
##### Reviewed points
@ -150,55 +216,105 @@ $ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
##### Comments
</screen></example>
</section>
</screen>
</example>
</section>
<section>
<title>New packages</title>
<section><title>New packages</title>
<para>
New packages are a common type of pull-requests. These pull requests
consists in adding a new nix-expression for a package.
</para>
<para>New packages are a common type of pull-requests. These pull requests
consists in adding a new nix-expression for a package.</para>
<para>
Reviewing process:
</para>
<para>Reviewing process:</para>
<itemizedlist>
<listitem><para>Add labels to the pull-request. (Requires commit
rights)</para>
<itemizedlist>
<listitem>
<para>
Add labels to the pull-request. (Requires commit rights)
</para>
<itemizedlist>
<listitem><para><literal>8.has: package (new)</literal> and any topic
label that fit the new package.</para></listitem>
<listitem>
<para>
<literal>8.has: package (new)</literal> and any topic label that fit the
new package.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the package versioning is fitting the
guidelines.</para></listitem>
<listitem><para>Ensure that the commit name is fitting the
guidelines.</para></listitem>
<listitem><para>Ensure that the meta field contains correct
information.</para>
</listitem>
<listitem>
<para>
Ensure that the package versioning is fitting the guidelines.
</para>
</listitem>
<listitem>
<para>
Ensure that the commit name is fitting the guidelines.
</para>
</listitem>
<listitem>
<para>
Ensure that the meta field contains correct information.
</para>
<itemizedlist>
<listitem><para>License must be checked to be fitting upstream
license.</para></listitem>
<listitem><para>Platforms should be set or the package will not get binary
substitutes.</para></listitem>
<listitem><para>A maintainer must be set, this can be the package
submitter or a community member that accepts to take maintainership of
the package.</para></listitem>
<listitem>
<para>
License must be checked to be fitting upstream license.
</para>
</listitem>
<listitem>
<para>
Platforms should be set or the package will not get binary substitutes.
</para>
</listitem>
<listitem>
<para>
A maintainer must be set, this can be the package submitter or a
community member that accepts to take maintainership of the package.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the code contains no typos.</para></listitem>
<listitem><para>Ensure the package source.</para>
</listitem>
<listitem>
<para>
Ensure that the code contains no typos.
</para>
</listitem>
<listitem>
<para>
Ensure the package source.
</para>
<itemizedlist>
<listitem><para>Mirrors urls should be used when
available.</para></listitem>
<listitem><para>The most appropriate function should be used (e.g.
packages from GitHub should use
<literal>fetchFromGitHub</literal>).</para></listitem>
<listitem>
<para>
Mirrors urls should be used when available.
</para>
</listitem>
<listitem>
<para>
The most appropriate function should be used (e.g. packages from GitHub
should use <literal>fetchFromGitHub</literal>).
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Building the package locally.</para></listitem>
<listitem><para>Running every binary.</para></listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Building the package locally.
</para>
</listitem>
<listitem>
<para>
Running every binary.
</para>
</listitem>
</itemizedlist>
<example><title>Sample template for a new package review</title>
<example>
<title>Sample template for a new package review</title>
<screen>
##### Reviewed points
@ -220,58 +336,107 @@ $ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
##### Comments
</screen></example>
</section>
</screen>
</example>
</section>
<section>
<title>Module updates</title>
<section><title>Module updates</title>
<para>
Module updates are submissions changing modules in some ways. These often
contains changes to the options or introduce new options.
</para>
<para>Module updates are submissions changing modules in some ways. These often
contains changes to the options or introduce new options.</para>
<para>
Reviewing process
</para>
<para>Reviewing process</para>
<itemizedlist>
<listitem><para>Add labels to the pull-request. (Requires commit
rights)</para>
<itemizedlist>
<listitem>
<para>
Add labels to the pull-request. (Requires commit rights)
</para>
<itemizedlist>
<listitem><para><literal>8.has: module (update)</literal> and any topic
label that fit the module.</para></listitem>
<listitem>
<para>
<literal>8.has: module (update)</literal> and any topic label that fit
the module.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the module maintainers are notified.</para>
</listitem>
<listitem>
<para>
Ensure that the module maintainers are notified.
</para>
<itemizedlist>
<listitem><para>Mention-bot notify GitHub users based on the submitted
changes, but it can happen that it miss some of the package
maintainers.</para></listitem>
<listitem>
<para>
Mention-bot notify GitHub users based on the submitted changes, but it
can happen that it miss some of the package maintainers.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the module tests, if any, are
succeeding.</para></listitem>
<listitem><para>Ensure that the introduced options are correct.</para>
</listitem>
<listitem>
<para>
Ensure that the module tests, if any, are succeeding.
</para>
</listitem>
<listitem>
<para>
Ensure that the introduced options are correct.
</para>
<itemizedlist>
<listitem><para>Type should be appropriate (string related types differs
in their merging capabilities, <literal>optionSet</literal> and
<literal>string</literal> types are deprecated).</para></listitem>
<listitem><para>Description, default and example should be
provided.</para></listitem>
<listitem>
<para>
Type should be appropriate (string related types differs in their
merging capabilities, <literal>optionSet</literal> and
<literal>string</literal> types are deprecated).
</para>
</listitem>
<listitem>
<para>
Description, default and example should be provided.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that option changes are backward compatible.</para>
</listitem>
<listitem>
<para>
Ensure that option changes are backward compatible.
</para>
<itemizedlist>
<listitem><para><literal>mkRenamedOptionModule</literal> and
<literal>mkAliasOptionModule</literal> functions provide way to make
option changes backward compatible.</para></listitem>
<listitem>
<para>
<literal>mkRenamedOptionModule</literal> and
<literal>mkAliasOptionModule</literal> functions provide way to make
option changes backward compatible.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that removed options are declared with
<literal>mkRemovedOptionModule</literal></para></listitem>
<listitem><para>Ensure that changes that are not backward compatible are
mentioned in release notes.</para></listitem>
<listitem><para>Ensure that documentations affected by the change is
updated.</para></listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Ensure that removed options are declared with
<literal>mkRemovedOptionModule</literal>
</para>
</listitem>
<listitem>
<para>
Ensure that changes that are not backward compatible are mentioned in
release notes.
</para>
</listitem>
<listitem>
<para>
Ensure that documentations affected by the change is updated.
</para>
</listitem>
</itemizedlist>
<example><title>Sample template for a module update review</title>
<example>
<title>Sample template for a module update review</title>
<screen>
##### Reviewed points
@ -288,51 +453,89 @@ $ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
##### Comments
</screen></example>
</section>
</screen>
</example>
</section>
<section>
<title>New modules</title>
<section><title>New modules</title>
<para>
New modules submissions introduce a new module to NixOS.
</para>
<para>New modules submissions introduce a new module to NixOS.</para>
<itemizedlist>
<listitem>
<para>
Add labels to the pull-request. (Requires commit rights)
</para>
<itemizedlist>
<listitem>
<para>
<literal>8.has: module (new)</literal> and any topic label that fit the
module.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Ensure that the module tests, if any, are succeeding.
</para>
</listitem>
<listitem>
<para>
Ensure that the introduced options are correct.
</para>
<itemizedlist>
<listitem>
<para>
Type should be appropriate (string related types differs in their
merging capabilities, <literal>optionSet</literal> and
<literal>string</literal> types are deprecated).
</para>
</listitem>
<listitem>
<para>
Description, default and example should be provided.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Ensure that module <literal>meta</literal> field is present
</para>
<itemizedlist>
<listitem>
<para>
Maintainers should be declared in <literal>meta.maintainers</literal>.
</para>
</listitem>
<listitem>
<para>
Module documentation should be declared with
<literal>meta.doc</literal>.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Ensure that the module respect other modules functionality.
</para>
<itemizedlist>
<listitem>
<para>
For example, enabling a module should not open firewall ports by
default.
</para>
</listitem>
</itemizedlist>
</listitem>
</itemizedlist>
<itemizedlist>
<listitem><para>Add labels to the pull-request. (Requires commit
rights)</para>
<itemizedlist>
<listitem><para><literal>8.has: module (new)</literal> and any topic label
that fit the module.</para></listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the module tests, if any, are
succeeding.</para></listitem>
<listitem><para>Ensure that the introduced options are correct.</para>
<itemizedlist>
<listitem><para>Type should be appropriate (string related types differs
in their merging capabilities, <literal>optionSet</literal> and
<literal>string</literal> types are deprecated).</para></listitem>
<listitem><para>Description, default and example should be
provided.</para></listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that module <literal>meta</literal> field is
present</para>
<itemizedlist>
<listitem><para>Maintainers should be declared in
<literal>meta.maintainers</literal>.</para></listitem>
<listitem><para>Module documentation should be declared with
<literal>meta.doc</literal>.</para></listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the module respect other modules
functionality.</para>
<itemizedlist>
<listitem><para>For example, enabling a module should not open firewall
ports by default.</para></listitem>
</itemizedlist>
</listitem>
</itemizedlist>
<example><title>Sample template for a new module review</title>
<example>
<title>Sample template for a new module review</title>
<screen>
##### Reviewed points
@ -350,32 +553,41 @@ $ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
##### Comments
</screen></example>
</section>
</screen>
</example>
</section>
<section>
<title>Other submissions</title>
<section><title>Other submissions</title>
<para>
Other type of submissions requires different reviewing steps.
</para>
<para>Other type of submissions requires different reviewing steps.</para>
<para>
If you consider having enough knowledge and experience in a topic and would
like to be a long-term reviewer for related submissions, please contact the
current reviewers for that topic. They will give you information about the
reviewing process. The main reviewers for a topic can be hard to find as
there is no list, but checking past pull-requests to see who reviewed or
git-blaming the code to see who committed to that topic can give some hints.
</para>
<para>If you consider having enough knowledge and experience in a topic and
would like to be a long-term reviewer for related submissions, please contact
the current reviewers for that topic. They will give you information about the
reviewing process.
The main reviewers for a topic can be hard to find as there is no list, but
checking past pull-requests to see who reviewed or git-blaming the code to see
who committed to that topic can give some hints.</para>
<para>
Container system, boot system and library changes are some examples of the
pull requests fitting this category.
</para>
</section>
<section>
<title>Merging pull-requests</title>
<para>Container system, boot system and library changes are some examples of the
pull requests fitting this category.</para>
<para>
It is possible for community members that have enough knowledge and
experience on a special topic to contribute by merging pull requests.
</para>
</section>
<section><title>Merging pull-requests</title>
<para>It is possible for community members that have enough knowledge and
experience on a special topic to contribute by merging pull requests.</para>
<para>TODO: add the procedure to request merging rights.</para>
<para>
TODO: add the procedure to request merging rights.
</para>
<!--
The following paragraph about how to deal with unactive contributors is just a
@ -386,10 +598,11 @@ policy.
three months will have their commit rights revoked.</para>
-->
<para>In a case a contributor leaves definitively the Nix community, he should
create an issue or notify the mailing list with references of packages and
modules he maintains so the maintainership can be taken over by other
contributors.</para>
</section>
<para>
In a case a contributor leaves definitively the Nix community, he should
create an issue or notify the mailing list with references of packages and
modules he maintains so the maintainership can be taken over by other
contributors.
</para>
</section>
</chapter>

4033
doc/stdenv.xml
View File

File diff suppressed because it is too large Load Diff

878
doc/submitting-changes.xml
View File

@ -1,447 +1,513 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-submitting-changes">
<title>Submitting changes</title>
<section>
<title>Making patches</title>
<title>Submitting changes</title>
<section>
<title>Making patches</title>
<itemizedlist>
<listitem>
<para>Read <link xlink:href="https://nixos.org/nixpkgs/manual/">Manual (How to write packages for Nix)</link>.</para>
</listitem>
<listitem>
<para>Fork the repository on GitHub.</para>
</listitem>
<listitem>
<para>Create a branch for your future fix.
<itemizedlist>
<listitem>
<para>You can make branch from a commit of your local <command>nixos-version</command>. That will help you to avoid additional local compilations. Because you will receive packages from binary cache.
<itemizedlist>
<listitem>
<para>For example: <command>nixos-version</command> returns <command>15.05.git.0998212 (Dingo)</command>. So you can do:</para>
</listitem>
</itemizedlist>
<itemizedlist>
<listitem>
<para>
Read <link xlink:href="https://nixos.org/nixpkgs/manual/">Manual (How to
write packages for Nix)</link>.
</para>
</listitem>
<listitem>
<para>
Fork the repository on GitHub.
</para>
</listitem>
<listitem>
<para>
Create a branch for your future fix.
<itemizedlist>
<listitem>
<para>
You can make branch from a commit of your local
<command>nixos-version</command>. That will help you to avoid
additional local compilations. Because you will receive packages from
binary cache.
<itemizedlist>
<listitem>
<para>
For example: <command>nixos-version</command> returns
<command>15.05.git.0998212 (Dingo)</command>. So you can do:
</para>
</listitem>
</itemizedlist>
<screen>
$ git checkout 0998212
$ git checkout -b 'fix/pkg-name-update'
</screen>
</para>
</listitem>
<listitem>
<para>Please avoid working directly on the <command>master</command> branch.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>Make commits of logical units.
<itemizedlist>
<listitem>
<para>If you removed pkgs, made some major NixOS changes etc., write about them in <command>nixos/doc/manual/release-notes/rl-unstable.xml</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>Check for unnecessary whitespace with <command>git diff --check</command> before committing.</para>
</listitem>
<listitem>
<para>Format the commit in a following way:</para>
</para>
</listitem>
<listitem>
<para>
Please avoid working directly on the <command>master</command> branch.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
Make commits of logical units.
<itemizedlist>
<listitem>
<para>
If you removed pkgs, made some major NixOS changes etc., write about
them in
<command>nixos/doc/manual/release-notes/rl-unstable.xml</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
Check for unnecessary whitespace with <command>git diff --check</command>
before committing.
</para>
</listitem>
<listitem>
<para>
Format the commit in a following way:
</para>
<programlisting>
(pkg-name | nixos/&lt;module>): (from -> to | init at version | refactor | etc)
Additional information.
</programlisting>
<itemizedlist>
<listitem>
<para>
Examples:
<itemizedlist>
<listitem>
<para>
<command>nginx: init at 2.0.1</command>
</para>
</listitem>
<listitem>
<para>
<command>firefox: 54.0.1 -> 55.0</command>
</para>
</listitem>
<listitem>
<para>
<command>nixos/hydra: add bazBaz option</command>
</para>
</listitem>
<listitem>
<para>
<command>nixos/nginx: refactor config generation</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Test your changes. If you work with
<itemizedlist>
<listitem>
<para>
nixpkgs:
<itemizedlist>
<listitem>
<para>
update pkg ->
<itemizedlist>
<listitem>
<para>
<command>nix-env -i pkg-name -f &lt;path to your local nixpkgs
folder&gt;</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
add pkg ->
<itemizedlist>
<listitem>
<para>
Make sure it's in
<command>pkgs/top-level/all-packages.nix</command>
</para>
</listitem>
<listitem>
<para>
<command>nix-env -i pkg-name -f &lt;path to your local nixpkgs
folder&gt;</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
<emphasis>If you don't want to install pkg in you
profile</emphasis>.
<itemizedlist>
<listitem>
<para>
<command>nix-build -A pkg-attribute-name &lt;path to your local
nixpkgs folder&gt;/default.nix</command> and check results in the
folder <command>result</command>. It will appear in the same
directory where you did <command>nix-build</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
If you did <command>nix-env -i pkg-name</command> you can do
<command>nix-env -e pkg-name</command> to uninstall it from your
system.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
NixOS and its modules:
<itemizedlist>
<listitem>
<para>
You can add new module to your NixOS configuration file (usually
it's <command>/etc/nixos/configuration.nix</command>). And do
<command>sudo nixos-rebuild test -I nixpkgs=&lt;path to your local
nixpkgs folder&gt; --fast</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
If you have commits <command>pkg-name: oh, forgot to insert
whitespace</command>: squash commits in this case. Use <command>git rebase
-i</command>.
</para>
</listitem>
<listitem>
<para>
Rebase you branch against current <command>master</command>.
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Submitting changes</title>
<itemizedlist>
<listitem>
<para>Examples:
<itemizedlist>
<listitem>
<para>
<command>nginx: init at 2.0.1</command>
</para>
</listitem>
<listitem>
<para>
<command>firefox: 54.0.1 -> 55.0</command>
</para>
</listitem>
<listitem>
<para>
<command>nixos/hydra: add bazBaz option</command>
</para>
</listitem>
<listitem>
<para>
<command>nixos/nginx: refactor config generation</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>Test your changes. If you work with
<itemizedlist>
<listitem>
<para>nixpkgs:
<itemizedlist>
<listitem>
<para>update pkg ->
<itemizedlist>
<listitem>
<para>
<command>nix-env -i pkg-name -f &lt;path to your local nixpkgs folder&gt;</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>add pkg ->
<itemizedlist>
<listitem>
<para>Make sure it's in <command>pkgs/top-level/all-packages.nix</command>
</para>
</listitem>
<listitem>
<para>
<command>nix-env -i pkg-name -f &lt;path to your local nixpkgs folder&gt;</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
<emphasis>If you don't want to install pkg in you profile</emphasis>.
<itemizedlist>
<listitem>
<para>
<command>nix-build -A pkg-attribute-name &lt;path to your local nixpkgs folder&gt;/default.nix</command> and check results in the folder <command>result</command>. It will appear in the same directory where you did <command>nix-build</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>If you did <command>nix-env -i pkg-name</command> you can do <command>nix-env -e pkg-name</command> to uninstall it from your system.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>NixOS and its modules:
<itemizedlist>
<listitem>
<para>You can add new module to your NixOS configuration file (usually it's <command>/etc/nixos/configuration.nix</command>).
And do <command>sudo nixos-rebuild test -I nixpkgs=&lt;path to your local nixpkgs folder&gt; --fast</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>If you have commits <command>pkg-name: oh, forgot to insert whitespace</command>: squash commits in this case. Use <command>git rebase -i</command>.</para>
</listitem>
<listitem>
<para>Rebase you branch against current <command>master</command>.</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Submitting changes</title>
<itemizedlist>
<listitem>
<para>Push your changes to your fork of nixpkgs.</para>
</listitem>
<listitem>
<para>Create pull request:
<itemizedlist>
<listitem>
<para>Write the title in format <command>(pkg-name | nixos/&lt;module>): improvement</command>.
<itemizedlist>
<listitem>
<para>If you update the pkg, write versions <command>from -> to</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>Write in comment if you have tested your patch. Do not rely much on <command>TravisCI</command>.</para>
</listitem>
<listitem>
<para>If you make an improvement, write about your motivation.</para>
</listitem>
<listitem>
<para>Notify maintainers of the package. For example add to the message: <command>cc @jagajaga @domenkozar</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</section>
<section>
<itemizedlist>
<listitem>
<para>
Push your changes to your fork of nixpkgs.
</para>
</listitem>
<listitem>
<para>
Create pull request:
<itemizedlist>
<listitem>
<para>
Write the title in format <command>(pkg-name | nixos/&lt;module>):
improvement</command>.
<itemizedlist>
<listitem>
<para>
If you update the pkg, write versions <command>from -> to</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
Write in comment if you have tested your patch. Do not rely much on
<command>TravisCI</command>.
</para>
</listitem>
<listitem>
<para>
If you make an improvement, write about your motivation.
</para>
</listitem>
<listitem>
<para>
Notify maintainers of the package. For example add to the message:
<command>cc @jagajaga @domenkozar</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Pull Request Template</title>
<para>
The pull request template helps determine what steps have been made for a
contribution so far, and will help guide maintainers on the status of a
change. The motivation section of the PR should include any extra details
the title does not address and link any existing issues related to the pull
request.
The pull request template helps determine what steps have been made for a
contribution so far, and will help guide maintainers on the status of a
change. The motivation section of the PR should include any extra details
the title does not address and link any existing issues related to the pull
request.
</para>
<para>When a PR is created, it will be pre-populated with some checkboxes detailed below:
<para>
When a PR is created, it will be pre-populated with some checkboxes detailed
below:
</para>
<section>
<title>Tested using sandboxing</title>
<para>
When sandbox builds are enabled, Nix will setup an isolated environment
for each build process. It is used to remove further hidden dependencies
set by the build environment to improve reproducibility. This includes
access to the network during the build outside of
<function>fetch*</function> functions and files outside the Nix store.
Depending on the operating system access to other resources are blocked
as well (ex. inter process communication is isolated on Linux); see <link
<title>Tested using sandboxing</title>
<para>
When sandbox builds are enabled, Nix will setup an isolated environment for
each build process. It is used to remove further hidden dependencies set by
the build environment to improve reproducibility. This includes access to
the network during the build outside of <function>fetch*</function>
functions and files outside the Nix store. Depending on the operating
system access to other resources are blocked as well (ex. inter process
communication is isolated on Linux); see
<link
xlink:href="https://nixos.org/nix/manual/#description-45">build-use-sandbox</link>
in Nix manual for details.
</para>
<para>
Sandboxing is not enabled by default in Nix due to a small performance
hit on each build. In pull requests for <link
xlink:href="https://github.com/NixOS/nixpkgs/">nixpkgs</link> people
are asked to test builds with sandboxing enabled (see <literal>Tested
using sandboxing</literal> in the pull request template) because
in<link
in Nix manual for details.
</para>
<para>
Sandboxing is not enabled by default in Nix due to a small performance hit
on each build. In pull requests for
<link
xlink:href="https://github.com/NixOS/nixpkgs/">nixpkgs</link>
people are asked to test builds with sandboxing enabled (see
<literal>Tested using sandboxing</literal> in the pull request template)
because
in<link
xlink:href="https://nixos.org/hydra/">https://nixos.org/hydra/</link>
sandboxing is also used.
</para>
<para>
Depending if you use NixOS or other platforms you can use one of the
following methods to enable sandboxing <emphasis role="bold">before</emphasis> building the package:
<itemizedlist>
<listitem>
<para>
<emphasis role="bold">Globally enable sandboxing on NixOS</emphasis>:
add the following to
<filename>configuration.nix</filename>
<screen>nix.useSandbox = true;</screen>
</para>
</listitem>
<listitem>
<para>
<emphasis role="bold">Globally enable sandboxing on non-NixOS platforms</emphasis>:
add the following to: <filename>/etc/nix/nix.conf</filename>
<screen>build-use-sandbox = true</screen>
</para>
</listitem>
</itemizedlist>
</para>
sandboxing is also used.
</para>
<para>
Depending if you use NixOS or other platforms you can use one of the
following methods to enable sandboxing
<emphasis role="bold">before</emphasis> building the package:
<itemizedlist>
<listitem>
<para>
<emphasis role="bold">Globally enable sandboxing on NixOS</emphasis>:
add the following to <filename>configuration.nix</filename>
<screen>nix.useSandbox = true;</screen>
</para>
</listitem>
<listitem>
<para>
<emphasis role="bold">Globally enable sandboxing on non-NixOS
platforms</emphasis>: add the following to:
<filename>/etc/nix/nix.conf</filename>
<screen>build-use-sandbox = true</screen>
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section>
<title>Built on platform(s)</title>
<para>
Many Nix packages are designed to run on multiple
platforms. As such, it's important to let the maintainer know which
platforms your changes have been tested on. It's not always practical to
test a change on all platforms, and is not required for a pull request to
be merged. Only check the systems you tested the build on in this
section.
</para>
<title>Built on platform(s)</title>
<para>
Many Nix packages are designed to run on multiple platforms. As such, it's
important to let the maintainer know which platforms your changes have been
tested on. It's not always practical to test a change on all platforms, and
is not required for a pull request to be merged. Only check the systems you
tested the build on in this section.
</para>
</section>
<section>
<title>Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)</title>
<para>
Packages with automated tests are much more likely to be merged in a
timely fashion because it doesn't require as much manual testing by the
maintainer to verify the functionality of the package. If there are
existing tests for the package, they should be run to verify your changes
do not break the tests. Tests only apply to packages with NixOS modules
defined and can only be run on Linux. For more details on writing and
running tests, see the <link
<title>Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)</title>
<para>
Packages with automated tests are much more likely to be merged in a timely
fashion because it doesn't require as much manual testing by the maintainer
to verify the functionality of the package. If there are existing tests for
the package, they should be run to verify your changes do not break the
tests. Tests only apply to packages with NixOS modules defined and can only
be run on Linux. For more details on writing and running tests, see the
<link
xlink:href="https://nixos.org/nixos/manual/index.html#sec-nixos-tests">section
in the NixOS manual</link>.
</para>
in the NixOS manual</link>.
</para>
</section>
<section>
<title>Tested compilation of all pkgs that depend on this change using <command>nox-review</command></title>
<para>
If you are updating a package's version, you can use nox to make sure all
packages that depend on the updated package still compile correctly. This
can be done using the nox utility. The <command>nox-review</command>
utility can look for and build all dependencies either based on
uncommited changes with the <literal>wip</literal> option or specifying a
github pull request number.
</para>
<para>
review uncommitted changes:
<screen>nix-shell -p nox --run "nox-review wip"</screen>
</para>
<para>
review changes from pull request number 12345:
<screen>nix-shell -p nox --run "nox-review pr 12345"</screen>
</para>
<title>Tested compilation of all pkgs that depend on this change using <command>nox-review</command></title>
<para>
If you are updating a package's version, you can use nox to make sure all
packages that depend on the updated package still compile correctly. This
can be done using the nox utility. The <command>nox-review</command>
utility can look for and build all dependencies either based on uncommited
changes with the <literal>wip</literal> option or specifying a github pull
request number.
</para>
<para>
review uncommitted changes:
<screen>nix-shell -p nox --run "nox-review wip"</screen>
</para>
<para>
review changes from pull request number 12345:
<screen>nix-shell -p nox --run "nox-review pr 12345"</screen>
</para>
</section>
<section>
<title>Tested execution of all binary files (usually in <filename>./result/bin/</filename>)</title>
<para>
It's important to test any executables generated by a build when you
change or create a package in nixpkgs. This can be done by looking in
<filename>./result/bin</filename> and running any files in there, or at a
minimum, the main executable for the package. For example, if you make a change
to <package>texlive</package>, you probably would only check the binaries
associated with the change you made rather than testing all of them.
</para>
<title>Tested execution of all binary files (usually in <filename>./result/bin/</filename>)</title>
<para>
It's important to test any executables generated by a build when you change
or create a package in nixpkgs. This can be done by looking in
<filename>./result/bin</filename> and running any files in there, or at a
minimum, the main executable for the package. For example, if you make a
change to <package>texlive</package>, you probably would only check the
binaries associated with the change you made rather than testing all of
them.
</para>
</section>
<section>
<title>Meets nixpkgs contribution standards</title>
<para>
The last checkbox is fits <link
<title>Meets nixpkgs contribution standards</title>
<para>
The last checkbox is fits
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md">CONTRIBUTING.md</link>.
The contributing document has detailed information on standards the Nix
community has for commit messages, reviews, licensing of contributions
you make to the project, etc... Everyone should read and understand the
standards the community has for contributing before submitting a pull
request.
</para>
The contributing document has detailed information on standards the Nix
community has for commit messages, reviews, licensing of contributions you
make to the project, etc... Everyone should read and understand the
standards the community has for contributing before submitting a pull
request.
</para>
</section>
</section>
<section>
<title>Hotfixing pull requests</title>
<itemizedlist>
<listitem>
<para>Make the appropriate changes in you branch.</para>
</listitem>
<listitem>
<para>Don't create additional commits, do
<itemizedlist>
<listitem>
<para><command>git rebase -i</command></para>
</listitem>
<listitem>
<para>
<command>git push --force</command> to your branch.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Commit policy</title>
<itemizedlist>
<listitem>
<para>Commits must be sufficiently tested before being merged, both for the master and staging branches.</para>
</listitem>
<listitem>
<para>Hydra builds for master and staging should not be used as testing platform, it's a build farm for changes that have been already tested.</para>
</listitem>
<listitem>
<para>When changing the bootloader installation process, extra care must be taken. Grub installations cannot be rolled back, hence changes may break people's installations forever. For any non-trivial change to the bootloader please file a PR asking for review, especially from @edolstra.</para>
</listitem>
</itemizedlist>
<section>
<title>Master branch</title>
</section>
<section>
<title>Hotfixing pull requests</title>
<itemizedlist>
<listitem>
<para>
It should only see non-breaking commits that do not cause mass rebuilds.
</para>
</listitem>
<listitem>
<para>
Make the appropriate changes in you branch.
</para>
</listitem>
<listitem>
<para>
Don't create additional commits, do
<itemizedlist>
<listitem>
<para>
<command>git rebase -i</command>
</para>
</listitem>
<listitem>
<para>
<command>git push --force</command> to your branch.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Staging branch</title>
</section>
<section>
<title>Commit policy</title>
<itemizedlist>
<listitem>
<para>
It's only for non-breaking mass-rebuild commits. That means it's not to
be used for testing, and changes must have been well tested already.
<link xlink:href="http://comments.gmane.org/gmane.linux.distributions.nixos/13447">Read policy here</link>.
</para>
</listitem>
<listitem>
<para>
If the branch is already in a broken state, please refrain from adding
extra new breakages. Stabilize it for a few days, merge into master,
then resume development on staging.
<link xlink:href="http://hydra.nixos.org/jobset/nixpkgs/staging#tabs-evaluations">Keep an eye on the staging evaluations here</link>.
If any fixes for staging happen to be already in master, then master can
be merged into staging.
</para>
</listitem>
<listitem>
<para>
Commits must be sufficiently tested before being merged, both for the
master and staging branches.
</para>
</listitem>
<listitem>
<para>
Hydra builds for master and staging should not be used as testing
platform, it's a build farm for changes that have been already tested.
</para>
</listitem>
<listitem>
<para>
When changing the bootloader installation process, extra care must be
taken. Grub installations cannot be rolled back, hence changes may break
people's installations forever. For any non-trivial change to the
bootloader please file a PR asking for review, especially from @edolstra.
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Stable release branches</title>
<section>
<title>Master branch</title>
<itemizedlist>
<itemizedlist>
<listitem>
<para>
If you're cherry-picking a commit to a stable release branch, always use
<command>git cherry-pick -xe</command> and ensure the message contains a
clear description about why this needs to be included in the stable
branch.
</para>
<para>An example of a cherry-picked commit would look like this:</para>
<screen>
<para>
It should only see non-breaking commits that do not cause mass rebuilds.
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Staging branch</title>
<itemizedlist>
<listitem>
<para>
It's only for non-breaking mass-rebuild commits. That means it's not to
be used for testing, and changes must have been well tested already.
<link xlink:href="http://comments.gmane.org/gmane.linux.distributions.nixos/13447">Read
policy here</link>.
</para>
</listitem>
<listitem>
<para>
If the branch is already in a broken state, please refrain from adding
extra new breakages. Stabilize it for a few days, merge into master, then
resume development on staging.
<link xlink:href="http://hydra.nixos.org/jobset/nixpkgs/staging#tabs-evaluations">Keep
an eye on the staging evaluations here</link>. If any fixes for staging
happen to be already in master, then master can be merged into staging.
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Stable release branches</title>
<itemizedlist>
<listitem>
<para>
If you're cherry-picking a commit to a stable release branch, always use
<command>git cherry-pick -xe</command> and ensure the message contains a
clear description about why this needs to be included in the stable
branch.
</para>
<para>
An example of a cherry-picked commit would look like this:
</para>
<screen>
nixos: Refactor the world.
The original commit message describing the reason why the world was torn apart.
@ -451,9 +517,7 @@ Reason: I just had a gut feeling that this would also be wanted by people from
the stone age.
</screen>
</listitem>
</itemizedlist>
</section>
</section>
</itemizedlist>
</section>
</section>
</chapter>