anchor.diff:  { lib, fetchurl, stdenv, zlib, lzo, libtasn1, nettle, pkgconfig, lzip
  -, guileBindings, guile, perl, gmp, autogen, libidn, p11_kit, unbound, libiconv
  +, guileBindings, guile, perl, gmp, autogen, libidn, p11_kit, unbound
   , tpmSupport ? false, trousers
   
   # Version dependent args
  
positive.code:   enableParallelBuilding = !guileBindings;
  
    buildInputs = [ lzo lzip nettle libtasn1 libidn p11_kit zlib gmp autogen ]
      ++ lib.optional (stdenv.isFreeBSD) libiconv
      ++ lib.optional (tpmSupport && stdenv.isLinux) trousers
      ++ [ unbound ]
      ++ lib.optional guileBindings guile;
  
  
negative.code: 
    meta = with lib; {
      description = "The GNU Transport Layer Security Library";
      homepage = http://www.gnu.org/software/gnutls/;
      license = licenses.lgpl21Plus;
      maintainers = with maintainers; [ eelco wkennington ];
  