Instead of `buildPackages` which is actually pkgsBuildHost. This makes sure that tools like `gdb` and `gcc` that we might depend on indirectly are the purely native ones (not versions for cross compiling).
This adds support for using nix flakes commands with hix. This is done by creating a hidden `.hix-flake` directory and passing the source in using `--override-input`.
It also includes a `hix init` command to add a `flake.nix` and `nix/hix.nix` configuration file.
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).
* Use builtins.fetchGit{allRefs=true;} if no ref provided.
this allows to not being explicit about non-default branches.
* Pass buildProject as arg to first level project modules,
so that it can be used in, eg., shell definition.
* Add hsPkgs to projects modules config.
* Add benchmarks to generated project.flake packages
There are now 4 project modules used to check the arguments passed to the various project functions:
* `project-common.nix` - Arguments used by all the project functions
* `stack-project.nix` - Used by the `stackProject` and `stackProject'` functions
* `cabal-project.nix` - Used by the `cabalProject` and `cabalProject'` functions
* `project.nix` - Just the `projectFileName` argument that is used by `project` and `project'` functions to determine whether to call `stackProject` or `cabalProject` function.
This also includes the `rawProject.args` that was mistakenly left out of #1141 causing #1142 and improvements for the docs for the use of the `shell` argument in `flake.nix` files.
Hamish Mackenzie
Jean-Baptiste Giraudeau
Hamish Mackenzie