anchor.diff:  }:
   
   let
  -  version = "3.38";
  +  version = "3.39";
   
     baseUrl = "https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases"
       + "/NSS_${stdenv.lib.replaceStrings ["."] ["_"] version}_RTM/src";
  
positive.code:   src = fetchurl {
      url = "${baseUrl}/${name}.tar.gz";
      hashOutput = false;
      sha256 = "2c643d3c08d6935f4d325f40743719b6990aa25a79ec2f8f712c99d086672f62";
    };
  
    buildInputs = [
  
negative.code: 
      srcVerification = fetchurl {
        failEarly = true;
        inherit (src)
          urls
          outputHash
          outputHashAlgo;
        fullOpts = {
          sha256Url = "${baseUrl}/SHA256SUMS";
        };
      };
    };
  
  