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).
* Add test.
* wip
* Fix merge regression
* Combine drv, drv.source and drv.dist for doctest
* Skip cabal-doctests test when cross compiling
* Add the --no-magic flag to the .cabal file for the cabal-doctests test.
This appears to be necessary on OSX.
The --no-magic flag stops the doctest executable from expanding path
arguments, trying to locate the package db, etc.
This shouldn't be necessary with cabal-doctest, since all the
necessary options to pass to doctest are computed when running the Setup.hs
script.
See
https://github.com/input-output-hk/haskell.nix/pull/427#issuecomment-605761780.
* Fix cabal-doctest support
* Skip cabal-doctest test plan cross compiling
* More fixes for cabal-doctest
* Skip cabal-doctest tests when cross compiling
Co-authored-by: Moritz Angermann <moritz.angermann@gmail.com>
Co-authored-by: Hamish Mackenzie <Hamish.Mackenzie@iohk.io>
Co-authored-by: Hamish Mackenzie <Hamish.K.Mackenzie@gmail.com>
Hamish Mackenzie
Hamish Mackenzie
