anchor.diff:  
   let
     pname = "icu4c";
  -  version = "4.4.1";
  +  version = "4.6";
   in
   
   stdenv.mkDerivation {
  
positive.code:   meta = {
      description = "Unicode and globalization support library";
      homepage = http://site.icu-project.org/;
      maintainers = [stdenv.lib.maintainers.raskin];
      platforms = stdenv.lib.platforms.all;
    };
  }
  
negative.code:   src = fetchurl {
      url = "http://download.icu-project.org/files/${pname}/${version}/${pname}-"
        + (stdenv.lib.replaceChars ["."] ["_"] version) + "-src.tgz";
      sha256 = "1z6zklqdf6pq7fckk8ar4vmfrnw79bih6yc8gwc7k2vx2alav8dm";
    };
  
    postUnpack = "
  