anchor.diff:  { stdenv
   , fetchurl
  -, perl
   
   , acl
   , gmp
  
positive.code:   passthru = {
      srcVerification = fetchurl rec {
        failEarly = true;
        urls = tarballUrls "8.28";
        pgpsigUrls = map (n: "${n}.sig") urls;
        pgpKeyFingerprint = "6C37 DC12 121A 5006 BC1D  B804 DF6F D971 3060 37D9";
        inherit (src) outputHashAlgo;
        outputHash = "1117b1a16039ddd84d51a9923948307cfa28c2cea03d1a2438742253df0a0c65";
      };
    };
  
  
negative.code:     "mirror://gnu/coreutils/coreutils-${version}.tar.xz"
    ];
  
    version = "8.29";
  in
  stdenv.mkDerivation rec {
    name = "coreutils-${version}";
  