anchor.diff:    defaultDependencies = [
       bzip2 flac speex icu opusWithCustomModes
       libevent expat libjpeg snappy
  -    libpng libxml2 libxslt v8
  +    libpng libxml2 libxslt
       xdg_utils yasm minizip libwebp
       libusb1 libexif
     ];
  
positive.code:     use_system_libusb = false; # http://crbug.com/266149
      use_system_skia = false;
      use_system_sqlite = false; # http://crbug.com/22208
      use_system_v8 = !versionOlder source.version "34.0.0.0";
    };
  
    opusWithCustomModes = libopus.override {
  
negative.code: # default dependencies
  , bzip2, flac, speex, icu, libopus
  , libevent, expat, libjpeg, snappy
  , libpng, libxml2, libxslt
  , xdg_utils, yasm, minizip, libwebp
  , libusb1, libexif, pciutils
  
  