anchor.diff:  , lib
   , fetchurl
   , autoPatchelfHook
  +, wrapGAppsHook
   , alsa-lib
   , cups
  -, libpulseaudio
   , libX11
   , libXScrnSaver
   , libXtst
   , mesa
   , nss
  +, gtk3
  +, libpulseaudio
   , systemd
  -, wrapGAppsHook
   }:
   
   stdenv.mkDerivation rec {
  
positive.code:     libXtst
      mesa
      nss
    ];
  
    dontWrapGApps = true;
  
    libPath = lib.makeLibraryPath [
      alsa-lib
      cups
      libpulseaudio
      libX11
      libXScrnSaver
      libXtst
      mesa
      nss
      systemd
    ];
  
  
negative.code:   '';
  
    installPhase = ''
      runHook preInstall
  
      cp -R $TMP/tetrio-desktop/{usr/share,opt} $out/
      ln -s $out/opt/TETR.IO/tetrio-desktop $out/bin/
  
      substituteInPlace $out/share/applications/tetrio-desktop.desktop \
        --replace "Exec=\"/opt/TETR.IO/tetrio-desktop\"" "Exec=\"$out/opt/TETR.IO/tetrio-desktop\""
  
      runHook postInstall
    '';
  
    postFixup = ''
      wrapProgram $out/opt/TETR.IO/tetrio-desktop \
        --prefix LD_LIBRARY_PATH : ${libPath}:$out/opt/TETR.IO \
        ''${gappsWrapperArgs[@]}
    '';
  
    meta = with lib; {
  