{
  description = "Convert go.mod/go.sum to Nix packages";

  inputs.nixpkgs.url = "github:NixOS/nixpkgs/master";

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

  outputs = { self, nixpkgs, utils }:
    {
      overlays.default = import ./overlay.nix;

      templates = {
        app = {
          path = ./templates/app;
          description = "Gomod2nix packaged application";
        };
      };
      defaultTemplate = self.templates.app;

    } //
    (utils.lib.eachDefaultSystem
      (system:
        let
          pkgs = nixpkgs.legacyPackages.${system};

          # The newer Darwin SDK does not exist in current (nixos-22.05) stable
          # branches, so just fallback to the default callPackage.
          callPackage = pkgs.darwin.apple_sdk_11_0.callPackage or pkgs.callPackage;

          inherit (callPackage ./builder {
            inherit gomod2nix;
          }) mkGoEnv buildGoApplication;
          gomod2nix = callPackage ./default.nix {
            inherit mkGoEnv buildGoApplication;
          };
        in
        {
          packages.default = gomod2nix;
          legacyPackages = {
            # we cannot put them in packages because they are builder functions
            inherit mkGoEnv buildGoApplication;
            # just have this here for convenience
            inherit gomod2nix;
          };
          devShells.default = callPackage ./shell.nix {
            inherit mkGoEnv gomod2nix;
          };
        })
    );
}