anchor.diff:      ++ lib.optional enableGTK3 gtk3
       ++ lib.optionals (!passthru.ffmpegSupport) [ gstreamer gst-plugins-base ];
   
  -  nativeBuildInputs = [ autoconf213 which gnused ];
  +  nativeBuildInputs = [ autoconf213 which gnused pkgconfig perl python ] ++ lib.optional enableGTK3 wrapGAppsHook;
   
     configureFlags =
       [ "--enable-application=browser"
  
positive.code:       patchelf --set-rpath "${lib.getLib libnotify
          }/lib:$(patchelf --print-rpath "$out"/lib/firefox-*/libxul.so)" \
            "$out"/lib/firefox-*/libxul.so
      '';
  
    meta = {
  
negative.code: 
        # Remove SDK cruft. FIXME: move to a separate output?
        rm -rf $out/share/idl $out/include $out/lib/firefox-devel-*
  
        # Needed to find Mozilla runtime
        gappsWrapperArgs+=(--argv0 "$out/bin/.firefox-wrapped")
      '';
  
    postFixup =
  