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