anchor.diff:    passthru = {
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "6.5";
  -      pgpsigUrls = map (n: "${n}.sig") urls;
  -      pgpKeyFingerprint = "EAF6 69B3 1E31 E1DE CBD1  1513 DDBC 579D AB37 FBA9";
  +      urls = tarballUrls "6.6";
         inherit (src) outputHashAlgo;
  -      outputHash = "77774b3f4a06c20705cc2ef1c804864422e3cf95235e965b1f00a46df7da5f62";
  +      outputHash = "9bb9ca00da53f26a7e5725eee49689cd4a1e18d25d5b061ac8b2053018d93d66";
  +      fullOpts = {
  +        pgpsigUrls = map (n: "${n}.sig") urls;
  +        pgpKeyFingerprint = "EAF6 69B3 1E31 E1DE CBD1  1513 DDBC 579D AB37 FBA9";
  +      };
       };
     };
   
  
positive.code:   src = fetchurl {
      urls = tarballUrls version;
      hashOutput = false;
      sha256 = "77774b3f4a06c20705cc2ef1c804864422e3cf95235e965b1f00a46df7da5f62";
    };
  
    nativeBuildInputs = [
  
negative.code:     "mirror://gnu/texinfo/texinfo-${version}.tar.xz"
    ];
  
    version = "6.6";
  in
  stdenv.mkDerivation rec {
    name = "texinfo-${version}";
  