Although the default ghc used by haskell.nix is ghc 8.6.5 many of
the tools used in haskell.nix are still built with the boot compiler
ghc 8.4.4. These include
* haskell-nix.cabal-install
* haskell-nix.alex
* haskell-nix.happy
This change updates those to ghc 8.6.5 and includes materializations
for the new versions.
When cabal-install is built it is careful to disable materialization
checks on the version of itself used during the build to avoid
infinite recursion.
There was a version of nix-tools built with the boot ghc which was
only used when `checkMaterialization = true`. It was used for
the boot versions of alex, happy and hscolour. These have been update
to use the default (ghc 8.6.5) version of nix-tools and
checkMaterialization is forced off when they are being used to build
ghc. This means the materialization will only be checked for these
when they are built independently (they are included in the test set
via haskellNixRoots).
Three new arguments are added to `default.nix`:
* `defaultCompilerNixName` if not specified "ghc865" is used
* `checkMaterialization` makes it easier to switch on materialization checks
* `system` defaults to `builtins.currentSystem`
This change also moves the work needed for hydra eval to the eval
system using a new `evalPackages` feature. This includes:
* Fetching from git with `fetchgit`
* Building scripts with `runCommand` and `writeTextFile`
* `git ls-files` in `cleanGit`
* running `cabal v2-configure`
* copying materialized files (we are not sure why this is necessary but
if we do not `cp -r` the files nix will not load them on hydra)
Reduce size of `make-config-files.nix` strings by around 80%.
These are unlikely to be the cause of hydra eval time memory
issues in the GB range, but were still quite large (around 10MB for the
`cabal-simple` test case).
There was issue causing excessive builds of the `git` package when
cross compiling. Gory details are a comment in `lib/defaults.nix`
but in short if you use `git` you need an extra `.buildPackages`
one is not enough because it depends on `gdb` and that will
be different in `buildPackages` compared to
`buildPackages.buildPackages`.
Adds missing materialization files for ghc 8.4.4 (only needed
when `checkMaterialization` is on because of other
materialiazations, but good to have).
The Overlays branch
This is a major reorganization in how haskell.nix is used, and marks our 1.0 release.
The branch doesn't build due to numerous issues that we believe to be with the CI
and not this branch. We expect only very minor adjustments prior to calling this the
official 1.0 release.
* Move iohk-nix patches into haskell.nix
This moves the customizations we did in iohk-nix
into haskell.nix via overlays and config.
Add bootPkgs logic
this moves the nuking of bootPkgs where it belongs. This should eventually still be
removed and replaced by a proper solution, that doesn't require the nuking of
bootPkgs.
Allow us to bootstrap binary ghcs and a cabal-install
With this we can do the following:
```
$ nix repl compiler/old-ghc-nix
nix-repl> :b (let pkgs = import <nixpkgs> {}; in with import ./. {}; import ./compiler/bootstrap/cabal-install.nix { inherit (pkgs) fetchurl stdenv zlib; inherit hackage
; ghc = ghc844; src = pkgs.fetchurl { url = "https://github.com/haskell/cabal/archive/Cabal-v3.0.0.0-rc3.tar.gz"; sha256 = "1zl2mgg8307ykq3v8nmafc6zdhhj1cw7w8ffpap16dsm6
5lbnx33"; }; })
```
which wile it may look daunting, will allow us to bootstrap a
cabal-install with a ghc. From that point onwards, we should be able to
build any hackage package via haskell.nix.
Pass through cabal-install version
Better threading of arguments.
Add bootstrap overlay
Allow alex + happy to be built
This still has a wart: we need nix-tools, and for that we use the ghc865 from
nixpkgs. Ideally we'd build nix-tools against a specific ghc, but then
we'd need a build expression for that.
Make ghcjs work
Building something like this:
```
nix build '(with import ./. { nixpkgs = ../nixpkgs; nixpkgsArgs = { crossSystem = { config = "js-unknown-ghcjs"; }; }; }; (haskell-nix.hackage-package { name = "hello"; version = "1.0.0.2"; })).components.exes.hello'
```
will now work. Assuming `nixpkgs` has been appropriately patched to support the `js-unknown-ghcjs` triple.
Also: this will need an additional `Cabal` patch, to make `Cabal` understand what it needs to do with: `dist/build/hello/hello: copyFile: does not exist (No such file or directory)`
It needs to learn that `dist/build/hello/hello.jsexe` is what it wants to copy and that that is a directory. Luckily we do have some code in Cabal already that does this for `.exe` on windows.
Build `js-unknown-ghcjs` packages with haskell.nix
Using the following expression:
```
with import ./. { nixpkgs = ../nixpkgs; nixpkgsArgs = { crossSystem = { config = "js-unknown-ghcjs"; }; }; };
let Cabal = buildPackages.haskell-nix.hackage-package {
name = "Cabal"; version = "2.4.1.0";
modules = [
{ packages.Cabal.patches = [ ./Cabal-install-folder.diff ]; }
];
}; in
(haskell-nix.hackage-package {
name = "hello"; version = "1.0.0.2";
modules = [
({config, ... }:{ packages.hello.package.setup-depends = [ Cabal ]; })
];}).components.exes.hello
```
in a `test.nix` file. And running
```
nix build -f ./test.nix
```
on it, will produce
```
./result
├── bin
│ └── hello.jsexe
│ ├── all.js
│ ├── all.js.externs
│ ├── index.html
│ ├── lib.js
│ ├── manifest.webapp
│ ├── out.frefs.js
│ ├── out.frefs.json
│ ├── out.js
│ ├── out.stats
│ ├── rts.js
│ └── runmain.js
└── share
└── doc
└── x86_64-linux-ghc-8.6.5
└── hello-1.0.0.2
└── LICENSE
6 directories, 12 files
```
