error($c, "Build cannot be downloaded as a closure or Nix package.")

    notFound($c, "Build cannot be downloaded as a closure or Nix package.")

    error($c, "Path " . $build->outpath . " is no longer available.")

    notFound($c, "Path " . $build->outpath . " is no longer available.")

        # !!! better do this in getLatestBuilds with a join.
        next unless $build->buildproducts->find({type => "nix-build"}); 

        "  ManifestVersion: 3\n" .

        "  ManifestVersion: 4\n" .