anchor.diff:    src = fetchurl {
       urls = tarballUrls version;
       hashOutput = false;
  -    sha256 = "4c4bcbc90116932e3acd37b37812d8653b1b189c1904985898e860af818aee69";
  +    sha256 = "4f93aac6fecb7da2b92871bb9ee33032be6a87b174f54abf8ddf0911a22d29d2";
     };
   
     postPatch = ''
  
positive.code:     "mirror://gnupg/libgpg-error/libgpg-error-${version}.tar.bz2"
    ];
  
    version = "1.26";
  in
  stdenv.mkDerivation rec {
    name = "libgpg-error-${version}";
  
negative.code:   passthru = {
      srcVerification = fetchurl rec {
        failEarly = true;
        urls = tarballUrls "1.27";
        pgpsigUrls = map (n: "${n}.sig") urls;
        inherit (gnupg.srcVerification) pgpKeyFingerprints;
        outputHash = "4f93aac6fecb7da2b92871bb9ee33032be6a87b174f54abf8ddf0911a22d29d2";
        inherit (src) outputHashAlgo;
      };
    };
  