anchor.diff:  assert cupsSupport -> cups != null;
   
   let
  -  meta = {
  +  meta_common = {
       homepage = "http://www.gnu.org/software/ghostscript/";
       description = "GNU Ghostscript, a PostScript interpreter";
   
  
positive.code:       sha256 = "0zqa6ggbkdqiszsywgrra4ij0sddlmrfa50bx2mh568qid4ga0a2";
      };
  
      inherit meta;
      patches = [ ./purity.patch ];
    };
  
  
negative.code:       url = "http://downloads.ghostscript.com/public/${name}.tar.bz2";
        sha256 = "014f10rxn4ihvcr1frby4szd1jvkrwvmdhnbivpp55c9fssx3b05";
      };
      meta = meta_common // {
        homepage = "http://www.ghostscript.com/";
        description = "GPL Ghostscript, a PostScript interpreter";
      };
  