anchor.diff:    src = fetchurl {
       urls = tarballUrls version;
       hashOutput = false;
  -    sha256 = "fe8208133e73e47afc3251c08d2c21c5a60160165a8ab8b669c43a420e4ec680";
  +    sha256 = "0f8c0fb1b0db4681adb75c3ba0dd77a0472b1b359b9e80efd79fc27b4352132c";
     };
   
     setupHook = ./setup-hook.sh;
  
positive.code:     libPrefix = "lib/perl5/site_perl";
      srcVerification = fetchurl rec {
        failEarly = true;
        urls = tarballUrls "5.26.1";
        outputHash = "fe8208133e73e47afc3251c08d2c21c5a60160165a8ab8b669c43a420e4ec680";
        inherit (src) outputHashAlgo;
        sha256Urls = map (n: "${n}.sha256.txt") urls;
        sha1Urls = map (n: "${n}.sha1.txt") urls;
  
negative.code:     "mirror://cpan/src/5.0/perl-${version}.tar.xz"
    ];
  
    version = "5.26.2";
  in
  stdenv.mkDerivation rec {
    name = "perl-${version}";
  