flake.nix

{
  description = "PyF";

  inputs.flake-utils.url = "github:numtide/flake-utils";
  inputs.hls.url = "github:haskell/haskell-language-server/ghc_922_nix";

  # Broken: see https://github.com/NixOS/nix/issues/5621
  nixConfig.extra-substituters =
    [ "https://haskell-language-server.cachix.org" ];
  nixConfig.extra-trusted-public-keys = [
    "haskell-language-server.cachix.org-1:juFfHrwkOxqIOZShtC4YC1uT1bBcq2RSvC7OMKx0Nz8="
  ];

  outputs = { self, nixpkgs, flake-utils, hls }:
    flake-utils.lib.eachDefaultSystem (system:
      let pkgs = nixpkgs.legacyPackages.${system};
      in rec {
        defaultPackage = (pkgs.haskell.packages.ghc922.override {
          overrides = self: super:
            with pkgs.haskell.lib; {
              OpenGL = doJailbreak super.OpenGL;
              gloss-rendering = doJailbreak super.gloss-rendering;
              gloss = doJailbreak super.gloss;
            };
        }).callCabal2nix "LambdaBridge" ./. { };
        devShell = defaultPackage.env.overrideAttrs (old: {
          nativeBuildInputs = old.nativeBuildInputs ++ (with pkgs; [
            cabal-install

            self.inputs.hls.packages.${system}."haskell-language-server-92"
          ]);
        });
      });
}