anchor.diff:    src = fetchurl {
       urls = tarballUrls version;
       hashOutput = false;
  -    sha256 = "46942627d5d0ca11720fec18d81fc38f7ef837ea4197c1f630e71ce0d470b11e";
  +    sha256 = "ae7a42df026550b85daca8389b6a60ba6313b0567f374392e54918588a411e94";
     };
   
     nativeBuildInputs = [
  
positive.code:   passthru = {
      srcVerification = fetchurl rec {
        failEarly = true;
        urls = tarballUrls "3.3";
        pgpsigUrls = map (n: "${n}.sig") urls;
        pgpKeyFingerprint = "343C 2FF0 FBEE 5EC2 EDBE  F399 F359 9FF8 28C6 7298";
        inherit (src) outputHashAlgo;
        outputHash = "46942627d5d0ca11720fec18d81fc38f7ef837ea4197c1f630e71ce0d470b11e";
      };
    };
  
  
negative.code:     "mirror://gnu/nettle/nettle-${version}.tar.gz"
    ];
  
    version = "3.4";
  in
  stdenv.mkDerivation rec {
    name = "nettle-${version}";
  