anchor.diff:    tarballUrls = base: patch: map (n: "${n}/util-linux-${version base patch}.tar") (baseUrls base);
   
     base = "2.30";
  -  patch = null;
  +  patch = "1";
   in
   stdenv.mkDerivation rec {
     name = "${type}util-linux-${version base patch}";
  
positive.code:   src = fetchurl {
      urls = map (n: "${n}.xz") (tarballUrls base patch);
      hashOutput = false;
      sha256 = "c208a4ff6906cb7f57940aa5bc3a6eed146e50a7cc0a092f52ef2ab65057a08d";
    };
  
    nativeBuildInputs = [
  
negative.code:   passthru = {
      srcVerification = fetchurl {
        failEarly = true;
        urls = map (n: "${n}.xz") (tarballUrls "2.30" "1");
        pgpsigUrls = map (n: "${n}.sign") (tarballUrls "2.30" "1");
        pgpsigSha256Urls = map (n: "${n}/sha256sums.asc") (baseUrls "2.30");
        pgpKeyFingerprint = "B0C6 4D14 301C C6EF AEDF  60E4 E4B7 1D5E EC39 C284";
        pgpDecompress = true;
        outputHash = "1be4363a91ac428c9e43fc04dc6d2c66a19ec1e36f1105bd4b481540be13b841";
        inherit (src) outputHashAlgo;
      };
    };
  