anchor.diff:  
     perl524 = common {
       version = "5.24.4";
  -    sha256 = "0w0r6v5k5hw5q1k3p4c7krcxidkj2qzsj5dlrlrxhm01n7fksbxz"; 
  +    sha256 = "0w0r6v5k5hw5q1k3p4c7krcxidkj2qzsj5dlrlrxhm01n7fksbxz";
     };
   
     perl526 = common {
  
positive.code:   libcLib = lib.getLib libc;
    crossCompiling = stdenv.buildPlatform != stdenv.hostPlatform;
    common = { version, sha256 }: stdenv.mkDerivation (rec {
      name = "perl-${version}";
  
      src = fetchurlBoot {
  
negative.code: 
      configurePlatforms = [ "build" "host" "target" ];
  
      # TODO merge setup hooks
      setupHook = ./setup-hook-cross.sh;
    });
  