anchor.diff:        alsaLib nspr nss libnotify xorg.pixman yasm mesa
         xorg.libXScrnSaver xorg.scrnsaverproto pysqlite
         xorg.libXext xorg.xextproto sqlite unzip makeWrapper
  -      hunspell libevent libstartup_notification libvpx /* cairo */
  +      hunspell libevent libstartup_notification /* libvpx */ /* cairo */
         gstreamer gst_plugins_base icu libpng jemalloc
         libpulseaudio # only headers are needed
       ]
  
positive.code: 
    firefox-unwrapped = common {
      pname = "firefox";
      version = "45.0.2";
      sha512 = "8c0b7afb41a1a405fe499299d1a8b1138dac52b9ad67bfc8761b70a26f330581c2aa1d76d67075896ec3a0c3f5367b8b58365ebc8b3a01f801fa37071b3de526";
    };
  
    firefox-esr-unwrapped = common {
  
negative.code:       "--disable-updater"
        "--enable-jemalloc"
        "--disable-gconf"
        "--enable-default-toolkit=cairo-gtk2"
      ]
      ++ lib.optional enableGTK3 "--enable-default-toolkit=cairo-gtk3"
      ++ (if debugBuild then [ "--enable-debug" "--enable-profiling" ]
  