anchor.diff:  { fetchurl, stdenv, perl }:
   
   stdenv.mkDerivation rec {
  -  name = "parallel-20150322";
  +  name = "parallel-20150522";
   
     src = fetchurl {
       url = "mirror://gnu/parallel/${name}.tar.bz2";
  -    sha256 = "1zsj1bd4zbwb4n9i0jgzs7vd5wkyg3xvj6s1q6s5fyn0pff7j01c";
  +    sha256 = "01pkckrad3d2i7mkw98zxymp22rsngyjknhh18i4m6hq82bijjjc";
     };
   
     patchPhase =
  
positive.code:          it possible to use output from GNU Parallel as input for other
           programs.
        '';
  
      homepage = http://www.gnu.org/software/parallel/;
  
      license = licenses.gpl3Plus;
  
      platforms = platforms.all;
      maintainers = with maintainers; [ pSub ];
    };
  
negative.code: 
    meta = with stdenv.lib; {
      description = "Shell tool for executing jobs in parallel";
      longDescription =
        '' GNU Parallel is a shell tool for executing jobs in parallel.  A job
           is typically a single command or a small script that has to be run
  