{
  checkPkgs,
  checkSystem,
  modularFlake,
  ...
}:
{
  outputs = with modularFlake.defaultOutputs; [ checks ];
  modules = [
    (
      {
        lib,
        hasSystem,
        pkgs,
        ...
      }:
      lib.optionalAttrs hasSystem {
        config = {
          checks.derivation = modularFlake.mkNop pkgs;
          checks.expr =
            assert 2 + 2 == 4;
            null;
        };
      }
    )
  ];
  fails = false;
  expectedOutput = {
    checks = {
      ${checkSystem} = {
        derivation = modularFlake.mkNop checkPkgs;
        expr = modularFlake.mkNop checkPkgs;
      };
    };
  };
}