ema/flake.nix

{
  description = "Ema project";
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/30d3d79b7d3607d56546dd2a6b49e156ba0ec634";
    flake-utils.url = "github:numtide/flake-utils";
    flake-utils.inputs.nixpkgs.follows = "nixpkgs";
    flake-compat.url = "github:edolstra/flake-compat";
    flake-compat.flake = false;
  };
  outputs = inputs@{ self, nixpkgs, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        name = "ema";
        pkgs = nixpkgs.legacyPackages.${system};
        emaProject = returnShellEnv:
          pkgs.haskellPackages.developPackage {
            inherit name returnShellEnv;
            root = ./.;
            withHoogle = false;
            overrides = self: super: with pkgs.haskell.lib; {
              # lvar = self.callCabal2nix "lvar" inputs.lvar { };
              # url-slug = inputs.url-slug.defaultPackage.${system};
              relude = self.callHackage "relude" "1.0.0.1" { }; # Not on nixpkgs, for some reason.
            };
            modifier = drv:
              pkgs.haskell.lib.addBuildTools drv
                (with pkgs.haskellPackages; pkgs.lib.lists.optionals returnShellEnv [
                  # Specify your build/dev dependencies here. 
                  cabal-fmt
                  cabal-install
                  ghcid
                  haskell-language-server
                  ormolu
                  pkgs.nixpkgs-fmt
                ]);
          };
      in
      rec {
        # Used by `nix build`
        defaultPackage = emaProject false;

        # Used by `nix develop`
        devShell = emaProject true;
      });
}