anchor.diff:    src = fetchurl {
       url = "http://download.icu-project.org/files/${pname}/${version}/${pname}-"
         + (stdenv.lib.replaceChars ["."] ["_"] version) + "-src.tgz";
  -    sha256 = "0qrhf9gsj38saxfzpzvlwp1jwdsxr06npdds5dbsc86shg0lz69l";
  +    sha256 = "1z6zklqdf6pq7fckk8ar4vmfrnw79bih6yc8gwc7k2vx2alav8dm";
     };
   
     postUnpack = "
  
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: 
  let
    pname = "icu4c";
    version = "4.6";
  in
  
  stdenv.mkDerivation {
  