anchor.diff:    passthru = {
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "1.8.1";
  +      urls = tarballUrls "1.8.2";
         pgpsigUrls = map (n: "${n}.sig") urls;
         pgpKeyFingerprints = [
           # Werner Koch
  
positive.code:     "mirror://gnupg/libgcrypt/libgcrypt-${version}.tar.bz2"
    ];
  
    version = "1.8.1";
  in
  stdenv.mkDerivation rec {
    name = "libgcrypt-${version}";
  
negative.code:   src = fetchurl {
      urls = tarballUrls version;
      hashOutput = false;
      sha256 = "c8064cae7558144b13ef0eb87093412380efa16c4ee30ad12ecb54886a524c07";
    };
  
    buildInputs = [
  