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).
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
It looks like we can't use 8.8 for booting due to
https://gitlab.haskell.org/ghc/ghc/-/issues/18143
* Adds nixpkgs 20.09 to get mingw-w64 version 6
(also needed for ghc 8.10 windows cross compile)
* Add materialization for ghc 8.10.2 windows cross
* Fix issue with harfbuzz override so it works with nixpkgs 20.09
* Fixes eval time issue for windows index-state test (turns off native-dns cabal flag for windows)
* Include exe extension for windows in coverage test
lib:ghc is still broken for ghc 8.10 (all variants), but it always has been and we should try to fix it properly, but it will be very tricky.
- 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.
Hamish Mackenzie
Shea Levy
Hamish Mackenzie
Samuel Evans-Powell