This adds a way to specify the `evalSystem` or `evalPackages` explicitly when calling the `project` functions.
Currently if we want to make a `flake` that supports multiple systems we have few options:
* Require builders for all the supported systems (even just for `nix flake show`).
* Pass `--impure` so that haskell.nix can see `builtins.currentSystem` to set up `pkgs.evalPackages` to use that. Unfortunately this prevents nix from caching some of the work it does and often results in it recalculating for each supported system when it would otherwise be cached and take no time at all.
* Add an overlay to replace `evalPackages`. This works, but it is not straight forward.
* Materialize the nix files for the project.
This change allows `evalSystem = "x86_64-linux";` to be passed telling `haskell.nix` to run `cabal` and `nix-tools` on that system. The user will have to have a builder for that system, but does not need to have builders for the others (unless building outputs for them).
* Improve support for external Hackage repositories
This change builds #535. `repository` blocks in `cabal.project` parsed and `cabal` is used to automatically downloaded them. Then `hackage-to-nix` is used to produce the nix required.
To make it work with restricted eval (on hydra for instance) we need to include a sha256 like this:
```
repository ghcjs-overlay
url: https://input-output-hk.github.io/hackage-overlay-ghcjs
secure: True
root-keys:
key-threshold: 0
--sha256: sha256-EPlLYPmIGtxeahlOspRzwJv+60N5mqrNC2BY4jZKceE=
```
To find the correct `sha256` put in an invalid one and attempt a build.
Fixes:
Warning: `stdenv.lib` is deprecated and will be removed in the next release. Please use `pkgs.lib` instead. For more information see https://github.com/NixOS/nixpkgs/issues/108938
Fixes ghcjs 8.6.5 and 8.8.4.
Uses emscripten for ghcjs 8.8 and adds scripts for building ghcjs 8.8.
Many fixes for ghcjs test failures.
Includes relocatableConfigFiles for making relocatable ghcjs bundles.
- Added the ability to generate coverage reports for packages and
projects.
- Outputs mix and tix information, as well as a HTML report.
- Added the "doCoverage" module option that allows users to choose
packages to enable coverage for.
- Added a "doCoverage" flag to the component builder that outputs HPC
information when coverage is enabled.
- Added the "overrideModules" library function to make it more
ergonomic fo users to enable coverage on existing projects.
- Modified the "check" builder to also output ".tix" files (if they
exist). This information is required to generate the coverage
report.
- Added a test for coverage.
It causes a lot of issues. To make this work:
* `shellFor` is updated to use `getAllComponents` instead of `.all`.
* `getAllComponents` is updated to work on the package rather than
the package config.
* Tests updated to not use `.library` or `.exes.X` where appropriate.
* Documentation updated.
* Out of date examples removed.
As a bonus `shellFor` now takes a `components` argument that might be
useful for limiting the dependencies of the shell to just the ones
needed for the components you intend to work on.
Changes to the interface of haskell.nix (from the changelog.md file):
* Removed `sources.nixpkgs-default`, use `sources.nixpkgs` instead.
* Removed `./nixpkgs` directory, use `(import ./. {}).sources`
or `./nix/sources.nix` instead.
* Removes V1 interface for details on how to fix old code see:
https://github.com/input-output-hk/haskell.nix/issues/709
* Removed defaultCompilerNixName.
* cabalProject, cabalProject', hackage-project and hackage-package
now require a `compiler-nix-name` argument.
* `haskell-nix.tool` and `.tools` now require a `compiler-nix-name` argument.
New functions `p.tool` and `p.tools` (where p is a project) do not.
Like `shellFor { tools = ... }` they will use the compiler nix name
from the project (including stack projects where it is derived from
the resolver).
* `haskell-nix.alex` and `haskell-nix.happy` have been removed. Use
`p.tool "alex" "3.2.5"` or `shellFor { tools = { alex = "3.2.5"; } }`.
* `haskell-nix.nix-tools` -> `haskell-nix.nix-tools.ghc883` (it includes
the hpack exe now).
* `haskell-nix.cabal-install` ->
`p.tool "cabal" "3.2.0.0"` or `shellFor { tools = { cabal = "3.2.0.0"; } }`
* `haskell-nix.haskellNixRoots` -> `haskell-nix.roots ghc883` or `p.roots`
Other changes:
Adds hpack executable to the nix-tools derivations.
Adds a `cabal-hpack` test to make sure `hpack` works with
`cabalProject`.
Reduces the number of calls to `cabalProject` (particularly when
checking materialization), by giving internal tools a per-compiler
attribute.
Uses happy 1.19.12 when building newer ghc versions.
Updates cabal-install 3.2.0.0 to use the source from github that
is compatible with ghc 8.10.1.
Updates the docs for callCabalProjectToNix.
Adds a license mapping to fix a common warning.
* Add support for external Hackage repositories
Currently haskell.nix is not able to build Cabal projects that depend on
packages from private Hackage repositories, as it make only main Hackage
available to cabal. This is unfortunate.
This commit adds this functionality, by allowing the user to pass
`extra-hackages` and `extra-hackage-tarballs` to `mkPkgSet` and
`callCabalToNix` respectively, to add as much extra repositories as
needed.
This repositories are first made available to Cabal when calling
`v2-configure`, resulting in correct plans. Later they are combined with
global Hackage when building dependencies of the local packages.
* Use cabal.project.freeze if available
Currently callCabalProjectToNix does not copy `cabal.project.freeze`
from source directory, leading to different build plans when building
components with nix and when building project with `cabal new-build`
inside `nix-shell`.
This behavior is undesired, so this commits fixes it.
* Add tests for extra-hackages functionality
Co-authored-by: Moritz Angermann <moritz.angermann@gmail.com>
