{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
  };
  outputs = { self, nixpkgs }:
    let
      name = "simple";
      system = "x86_64-linux";
      pkgs = nixpkgs.legacyPackages.${system};
      src = ./.;
    in
    {
      packages.${system}.default = derivation {
        inherit name src system;
        builder = with pkgs; "${bash}/bin/bash";
        args = [ "-c" "echo foo > $out" ];
      };
    };
}