anchor.diff:    passthru = {
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "1.16";
  +      urls = tarballUrls "1.17";
         pgpsigUrls = map (n: "${n}.sig") urls;
         pgpKeyFingerprint = "325F 650C 4C2B 6AD5 8807  327A 3602 B07F 55D0 C732";
         inherit (src) outputHashAlgo;
  -      outputHash = "c8a18bc6259da0c3eefefb018f8aa298fddc6f86c6fc0f0dec73270896ab512f";
  +      outputHash = "7cd8cc2e35b1aaede6084ea57cc9447752f498daaea854100a4bad567614977d";
       };
     };
   
  
positive.code: }:
  
  let
    version = "1.16";
  
    tarballUrls = version: [
      "mirror://gnu/gdbm/gdbm-${version}.tar.gz"
  
negative.code:   src = fetchurl {
      urls = tarballUrls version;
      hashOutput = false;
      sha256 = "7cd8cc2e35b1aaede6084ea57cc9447752f498daaea854100a4bad567614977d";
    };
  
    buildInputs = [
  