anchor.diff:      libPrefix = "lib/perl5/site_perl";
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "5.26.2";
  -      outputHash = "0f8c0fb1b0db4681adb75c3ba0dd77a0472b1b359b9e80efd79fc27b4352132c";
  +      urls = tarballUrls "5.28.0";
  +      outputHash = "059b3cb69970d8c8c5964caced0335b4af34ac990c8e61f7e3f90cd1c2d11e49";
         inherit (src) outputHashAlgo;
         sha256Urls = map (n: "${n}.sha256.txt") urls;
         sha1Urls = map (n: "${n}.sha1.txt") urls;
  
positive.code:   src = fetchurl {
      urls = tarballUrls version;
      hashOutput = false;
      sha256 = "0f8c0fb1b0db4681adb75c3ba0dd77a0472b1b359b9e80efd79fc27b4352132c";
    };
  
    setupHook = ./setup-hook.sh;
  
negative.code:     "mirror://cpan/src/5.0/perl-${version}.tar.xz"
    ];
  
    version = "5.28.0";
  in
  stdenv.mkDerivation rec {
    name = "perl-${version}";
  