anchor.diff:    buildInputs = [ perl ];
     doCheck = true;
   
  -  meta = {
  +  meta = with stdenv.lib; {
       description = "Shell tool for executing jobs in parallel";
   
       longDescription =
  
positive.code: 
      homepage = http://www.gnu.org/software/parallel/;
  
      license = stdenv.lib.licenses.gpl3Plus;
  
      platforms = stdenv.lib.platforms.all;
      maintainers = [ ];
    };
  }
  
negative.code: { fetchurl, stdenv, perl }:
  
  stdenv.mkDerivation rec {
    name = "parallel-20140922";
  
    src = fetchurl {
      url = "mirror://gnu/parallel/${name}.tar.bz2";
      sha256 = "0hxx1h2ba6y2y1vy02r2hzndid2b469hj08f0vlmpjqw5g4f52a5";
    };
  
    patchPhase =
  