anchor.diff:          xlibs.libXScrnSaver xlibs.scrnsaverproto pysqlite
           xlibs.libXext xlibs.xextproto sqlite unzip makeWrapper
           hunspell libevent libstartup_notification libvpx cairo
  -        gstreamer gst_plugins_base
  +        gstreamer gst_plugins_base icu
         ];
   
       configureFlags =
  
positive.code:         dbus dbus_glib pango freetype fontconfig alsaLib nspr nss libnotify
          xlibs.pixman yasm mesa sqlite file unzip pysqlite
          hunspell libevent libstartup_notification libvpx cairo
          gstreamer gst_plugins_base
        ];
  
      patches = [
  
negative.code:       "--with-system-libevent"
        "--with-system-libvpx"
        "--with-system-png"
        "--with-system-icu"
        "--enable-system-ffi"
        "--enable-system-hunspell"
        "--enable-system-pixman"
        "--enable-system-sqlite"
        "--enable-system-cairo"
        "--enable-startup-notification"
        # "--enable-content-sandbox"            # available since 26.0, but not much info available
        # "--enable-content-sandbox-reporter"   # keeping disabled for now
        "--disable-crashreporter"
        "--disable-tests"
        "--disable-necko-wifi" # maybe we want to enable this at some point
        "--disable-installer"
        "--disable-updater"
      ] ++ (if debugBuild then [ "--enable-debug" "--enable-profiling"]
                          else [ "--disable-debug" "--enable-release"
                                 "--enable-optimize" "--enable-strip" ]);
  
  
    xulrunner = stdenv.mkDerivation rec {
  