add Nix CI workflow; update Nix flake

.github/workflows/nix.yml

@@ -0,0 +1,21 @@
+name: nix
+
+on:
+ # run on every push to every branch (visibility doesn't matter)
+ push:
+ # don't want pull_request config, since it would run twice
+
+jobs:
+ nix-flake-build:
+ runs-on: ubuntu-latest
+ name: build (flake)
+ steps:
+ - uses: actions/checkout@v3
+ - uses: cachix/install-nix-action@v20
+ with:
+ nix_path: nixpkgs=channel:nixos-unstable
+ - uses: cachix/cachix-action@v12
+ with:
+ name: camfort
+ authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+ - run: nix build

flake.nix

@@ -8,18 +8,9 @@
  flake-parts.lib.mkFlake { inherit inputs; } {
  systems = nixpkgs.lib.systems.flakeExposed;
  imports = [ inputs.haskell-flake.flakeModule ];
- perSystem = { self', pkgs, ... }: {
- haskellProjects.default = {
- # packages.example.root = ./.; # This value is detected based on .cabal files
- # overrides = self: super: { };
- # devShell = {
- # enable = true; # Enabled by default
- # tools = hp: { fourmolu = hp.fourmolu; ghcid = null; };
- # hlsCheck.enable = true;
- # };
- };
- # haskell-flake doesn't set the default package, but you can do it here.
+ perSystem = { self', pkgs, config, ... }: {
  packages.default = self'.packages.fortran-src;
+ haskellProjects.default = {};
  };
  };
 }