{
  inputs = {
    utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, utils, ... }:
    utils.lib.eachDefaultSystem (system:
      let
        pname = "grump";
        version = "0.0.0";
        pkgs = nixpkgs.legacyPackages."${system}";

        buildInputs = with pkgs.ocamlPackages; [
          utop # required for dune utop
        ];

      in
      with pkgs;
      rec {
        defaultPackage = ocamlPackages.buildDunePackage rec {
          inherit pname version buildInputs;
          useDune2 = true;
          src = ./.;
        };
        devShell = mkShell {
          buildInputs = with ocamlPackages; [
            ocaml
            pkgs.dune_2
            utop
            pkgs.nixUnstable
            fswatch
          ];
        };
      });
}