anchor.diff:    passthru = {
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "1.7.3";
  +      urls = tarballUrls "1.7.5";
         pgpsigUrls = map (n: "${n}.sig") urls;
  -      pgpKeyFingerprint = "D869 2123 C406 5DEA 5E0F  3AB5 249B 39D2 4F25 E3B6";
  -      outputHash = "ddac6111077d0a1612247587be238c5294dd0ee4d76dc7ba783cc55fb0337071";
  +      pgpKeyFingerprints = [
  +        # Werner Koch
  +        "D869 2123 C406 5DEA 5E0F  3AB5 249B 39D2 4F25 E3B6"
  +        # NIIBE Yutaka
  +        "031E C253 6E58 0D8E A286  A9F2 2071 B08A 33BD 3F06"
  +      ];
  +      outputHash = "d1fea4128beef2bb30a470af6bafabccc503ced350534fb9dd8f5a53ffbae800";
         inherit (src) outputHashAlgo;
       };
     };
  
positive.code:   src = fetchurl {
      url = tarballUrls version;
      hashOutput = false;
      sha256 = "ddac6111077d0a1612247587be238c5294dd0ee4d76dc7ba783cc55fb0337071";
    };
  
    buildInputs = [
  
negative.code:     "mirror://gnupg/libgcrypt/libgcrypt-${version}.tar.bz2"
    ];
  
    version = "1.7.5";
  in
  stdenv.mkDerivation rec {
    name = "libgcrypt-${version}";
  