anchor.diff:    passthru = {
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "1.7.5";
  +      urls = tarballUrls "1.7.6";
         pgpsigUrls = map (n: "${n}.sig") urls;
         pgpKeyFingerprints = [
           # Werner Koch
  
positive.code:         # NIIBE Yutaka
          "031E C253 6E58 0D8E A286  A9F2 2071 B08A 33BD 3F06"
        ];
        outputHash = "d1fea4128beef2bb30a470af6bafabccc503ced350534fb9dd8f5a53ffbae800";
        inherit (src) outputHashAlgo;
      };
    };
  
negative.code:   src = fetchurl {
      url = tarballUrls version;
      hashOutput = false;
      sha256 = "626aafee84af9d2ce253d2c143dc1c0902dda045780cc241f39970fc60be05bc";
    };
  
    buildInputs = [
  