{ lib, ... }:
with lib;
{
  config.outputKinds = [
    (
      { hasSystem, ... }:
      optionalAttrs hasSystem {
        options = {
          packages = mkOption {
            type = with types; attrsOf package;
            description = "Executed by `nix build .#<name>`";
          };
        };
        outputs = { config, system, ... }: {
          packages.${system} = config.packages;
        };
      }
    )
  ];
}