anchor.diff:    enableOfficialBranding ? false
   }:
   
  -let version = "31.2.0"; in
  +let version = "31.4.0"; in
   let verName = "${version}"; in
   
   stdenv.mkDerivation rec {
  
positive.code: { stdenv, fetchurl, pkgconfig, m4, gtk, pango, perl, python, zip, libIDL
  , libjpeg, libpng, zlib, dbus, dbus_glib, bzip2, xlibs
  , freetype, fontconfig, file, alsaLib, nspr, nss, libnotify
  , yasm, mesa, sqlite, unzip, makeWrapper, pysqlite
  
negative.code:       hunspell libevent libstartup_notification cairo icu
      ] ++ [ m4 ];
  
    configurePhase = let configureFlags = [ "--enable-application=mail" ]
      # from firefox30Pkgs.commonConfigureFlags, but without gstreamer and libvpx
      ++ [
        "--with-system-jpeg"
  