anchor.diff:    src = fetchurl {
       urls = tarballUrls version;
       hashOutput = false;
  -    sha256 = "a446ac5e40b801edfc4f6ba50fdeb614dcfeb34ab0d8c6868e29f359b877c201";
  +    sha256 = "0ff7a59eeedff3865fa17151d656991f56d8835f593982d7327af5e0bf9a9668";
     };
   
     nativeBuildInputs = [
  
positive.code: }:
  
  let
    version = "2.0.4";
  
    tarballUrls = version: [
      "mirror://gnu/libidn/libidn2-${version}.tar.lz"
  
negative.code:   passthru = {
      srcVerification = fetchurl rec {
        failEarly = true;
        urls = tarballUrls "2.0.5";
        pgpsigUrls = map (n: "${n}.sig") urls;
        pgpKeyFingerprint = "1CB2 7DBC 9861 4B2D 5841  646D 0830 2DB6 A267 0428";
        inherit (src) outputHashAlgo;
        outputHash = "0ff7a59eeedff3865fa17151d656991f56d8835f593982d7327af5e0bf9a9668";
      };
    };
  
  