anchor.diff:  }:
   
   let
  -  name = "chrony-3.3";
  +  name = "chrony-3.4";
   
     baseUrls = [
       "https://download.tuxfamily.org/chrony/${name}"
  
positive.code: 
    src = fetchurl {
      urls = map (n: "${n}.tar.gz") baseUrls;
      multihash = "Qmf9XJVJCv25hnoYfzLSTsAzDLTAbEzNBwhbSxp2msLGkE";
      hashOutput = false;
      sha256 = "0d1fb2d5875032f2d5a86f3770374c87ee4c941916f64171e81f7684f2a73128";
    };
    
    buildInputs = [
  
negative.code:   passthru = {
      srcVerification = fetchurl {
        failEarly = true;
        inherit (src)
          urls
          outputHash
          outputHashAlgo;
        fullOpts = {
          pgpsigUrls = map (n: "${n}-tar-gz-asc.txt") baseUrls;
          pgpKeyFingerprint = "8B1F 4A9A DA73 D401 E308  5A0B 5FF0 6F29 BA1E 013B";
        };
      };
    };
  
  