anchor.diff:    passthru = {
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "4179" "1.8.18";
  -      pgpsigUrls = map (n: "${n}.asc") (tarballUrls "4180" "1.8.18");
  +      urls = tarballUrls "4203" "1.8.20";
  +      pgpsigUrls = map (n: "${n}.asc") (tarballUrls "4204" "1.8.20");
         pgpKeyFingerprint = "F5E1 1B9F FE91 1146 F41D  953D 78A1 B4DF E8F9 C57E";
         inherit (src) outputHashAlgo;
         outputHash = "b22d32b018f6a1016adba91abfcc63876cca999daa472dd86e953ddd41d00905";
  
positive.code:   src = fetchurl {
      urls = tarballUrls id version;
      hashOutput = false;
      multihash = "QmUCkePPFomf5KBJAHPNYfNtpNkGF7sDjeJ3CfXNhQtCvv";
      sha256 = "b22d32b018f6a1016adba91abfcc63876cca999daa472dd86e953ddd41d00905";
    };
  
    nativeBuildInputs = optionals (!libOnly) [
  
negative.code: }:
  
  let
    id = "4203";
    version = "1.8.20";
  
    tarballUrls = id: version: [
      "https://alioth.debian.org/frs/download.php/file/${id}/pcsc-lite-${version}.tar.bz2"
  