anchor.diff:        (ifMinVer "4.2" (enableFeature libaomSupport "libaom"))
         (lib.optionalString pulseaudioSupport "--enable-libpulse")
         (ifMinVer "2.5" (if sdlSupport && reqMin "3.2" then "--enable-sdl2" else null))
  -      (ifMinVer "1.2" "--enable-libsoxr")
  +      "--enable-libsoxr"
         "--enable-libx264"
         "--enable-libxvid"
         "--enable-libzimg"
  
positive.code:       "--enable-libass"
        "--enable-bzlib"
        "--enable-gnutls"
        (ifMinVer "1.0" "--enable-fontconfig")
        "--enable-libfreetype"
        "--enable-libmp3lame"
        (ifMinVer "1.2" "--enable-iconv")
        "--enable-libtheora"
        (ifMinVer "2.1" "--enable-libssh")
        (enableFeature vaapiSupport "vaapi")
  
negative.code:       "--enable-avdevice"
        "--enable-avfilter"
        "--enable-avformat"
        (ifVerOlder "5.0" "--enable-avresample")
        "--enable-avutil"
        "--enable-postproc"
        "--enable-swresample"
        "--enable-swscale"
  