anchor.diff:    src = fetchurl {
       urls = map (n: "${n}.xz") tarballUrls;
       hashOutput = false;
  -    sha256 = "8b40be383a603147ae29337136c00d1c634bdfdc169a30924a024596a7e30e92";
  +    sha256 = "180feff58fc0d965d23ea010aa2c69ead92ec318eb9b09cf737529aec62f3ef4";
     };
   
     nativeBuildInputs = [
  
positive.code:     gnused
    ];
  
    version = "2.18.0";
  
    tarballUrls = [
      "mirror://kernel/software/scm/git/git-${version}.tar"
  
negative.code:   passthru = {
      srcVerification = fetchurl {
        failEarly = true;
        inherit (src)
          urls
          outputHash
          outputHashAlgo;
        fullOpts = {
          pgpDecompress = true;
          pgpsigUrls = map (n: "${n}.sign") tarballUrls;
          pgpKeyFingerprint = "96E0 7AF2 5771 9559 80DA  D100 20D0 4E5A 7136 60A7";
        };
      };
    };
  
  