anchor.diff:    src = fetchurl {
       url = tarballUrls version;
       hashOutput = false;
  -    sha256 = "e62c7eac5ae7c0e7286db61ff82912e1c0b7a0c13706616e94a7dd729321b530";
  +    sha256 = "2cd04b7c887808be030254e8d77de11d3fe9d4505c39d4b15d2664ffe8bf9301";
     };
   
     buildInputs = optionals pcregrep [
  
positive.code:   passthru = {
      srcVerification = fetchurl rec {
        failEarly = true;
        urls = tarballUrls "8.41";
        pgpsigUrls = map (n: "${n}.sig") urls;
        pgpKeyFingerprint = "45F6 8D54 BBE2 3FB3 039B  46E5 9766 E084 FB0F 43D8";
        inherit (src) outputHash outputHashAlgo;
  
negative.code:     "mirror://sourceforge/pcre/pcre/${version}/pcre-${version}.tar.bz2"
    ];
  
    version = "8.42";
  in
  stdenv.mkDerivation rec {
    name = "pcre-${version}";
  