anchor.diff:  , vala
   , gtk-doc
   , nix
  +, nlohmann_json ? null
   , boost
   , meson
   , ninja
  
positive.code:     nix
      boost
    ] ++ lib.optional enableSystemd systemd
    ++ lib.optional enableBashCompletion bash-completion;
    nativeBuildInputs = [
      vala
  
negative.code: , enableSystemd ? stdenv.isLinux
  , systemd
  }:
  let
    nix_version = lib.removeSuffix nix.VERSION_SUFFIX nix.version;
    useNlohmann = lib.versionAtLeast "2.7" nix_version;
  in
  
  assert useNlohmann -> nlohmann_json != null;
  
  stdenv.mkDerivation rec {
    pname = "packagekit";
    version = "1.2.5.1pre";
  
    outputs = [ "out" "dev" "devdoc" ];
  
    src = fetchFromGitHub {
      owner = "PackageKit";
      repo = "PackageKit";
      rev = "33b847c49b4a42499e3c0f10fef62830c874e086";
      sha256 = "UDpMswf0EBwcoHTqoWiztXnIAwM69nM+S9MPsR24amw=";
    };
  
    buildInputs = [
  