anchor.diff:        "--disable-updater"
         "--disable-tests"
         "--enable-content-sandbox"
  -    ] ++ optionals (sqlite != null) [
         "--enable-system-sqlite"
  -    ] ++ [
         "--enable-safe-browsing"
         "--enable-url-classifier"
         "--enable-optimize"
         "--enable-approximate-location"
  -    ] ++ optionals (jemalloc != null) [
         "--enable-jemalloc"
  -    ] ++ [
         "--enable-strip"
         #"--enable-b2g-ril"
         #"--enable-b2g-bt"
  
positive.code:       # From firefox-40, using system cairo causes firefox to crash
        # frequently when it is doing background rendering in a tab.
        "--enable-system-cairo"
      ]*/ ++ optionals (pixman != null) [
        "--enable-system-pixman"
      ] ++ [
        #"--enable-necko-protocols={http,ftp,default,all,none}"
        "--disable-necko-wifi"
      ] ++ optionals (icu != null) [
        "--with-system-icu"
      ];
  
  
negative.code:     ] ++ [
        "--enable-pie"
        "--with-pthreads"
        "--with-system-nspr"
        #"--enable-posix-nspr-emulation"
        "--with-system-libevent"
        "--with-system-nss"
      ] ++ optionals (!isLinux && libjpeg != null) [
        # Enable libjpeg for platforms that don't support libjpeg-turbo
        "--with-system-jpeg"
      ] ++ [
        "--with-system-zlib"
        "--with-system-bz2"
        "--with-system-png"
        "--enable-system-hunspell"
        "--enable-system-ffi"
        # Linking fails with shared js
        #"--enable-shared-js"
        #"--with-java-bin-path"
        "--enable-application=browser"
      ] ++ optionals enableOfficialBranding [
        "--enable-official-branding"
      ] ++ [
        "--enable-default-toolkit=cairo-gtk3"
        #"--without-x"
        "--enable-startup-notification"
        "--disable-gconf"
        #"--enable-libproxy"
        #"--enable-gnomeui" # ??? gnome2 ???
        "--enable-raw"
        #"--enable-eme"
        "--with-system-libvpx"
        "--enable-alsa"
        "--enable-gstreamer=1.0"
        "--disable-crashreporter"
      ] ++ optionals (isLinux && libjpeg != null)[
        "--enable-libjpeg-turbo"
  