anchor.diff:          xorg.libXinerama
           xorg.libXfixes
           libpng12
  -        libidn
  +        libidn_134
           zlib
           gtk_engines
           freetype
  
positive.code: { stdenv
  , lib
  , requireFile
  , makeWrapper
  , libredirect
  
negative.code: }:
  
  let
    # In 56e1bdc7f9c (libidn: 1.34 -> 1.35), libidn.so.11 became libidn.so.12.
    # Citrix looks for the former so we build version 1.34 to please the binary
    libidn_134 = libidn.overrideDerivation (_: rec {
      name = "libidn-1.34";
      src = fetchurl {
        url = "mirror://gnu/libidn/${name}.tar.gz";
        sha256 = "0g3fzypp0xjcgr90c5cyj57apx1cmy0c6y9lvw2qdcigbyby469p";
      };
    });
  
    versionInfo = {
      "13.4.0" = rec {
        major     = "13";
  