anchor.diff:  { stdenv
   , fetchurl
  +, lib
   
   , iproute
   , lzo
  
positive.code: }:
  
  stdenv.mkDerivation rec {
    name = "openvpn-2.4.2";
  
    src = fetchurl {
      url = "https://swupdate.openvpn.net/community/releases/${name}.tar.gz";
      hashOutput = false;
      sha256 = "b24740c9d44a81eaf2befc4846d51445a520104321e32aaf0c135ed2e098a624";
    };
  
    buildInputs = [
  
negative.code:     srcVerification = fetchurl rec {
        failEarly = true;
        pgpsigUrl = map (n: "${n}.asc") src.urls;
        # https://openvpn.net/index.php/open-source/documentation/sig.html
        pgpKeyFingerprints = [
          # James Yonan
          "C699 B264 0C6D 404E 6454  A9AD 1D0B 4996 1FBF 51F3"
          # Samuli Seppänen
          "0330 0E11 FED1 6F59 715F  9996 C29D 97ED 198D 22A3"  # Old
          "6D04 F8F1 B017 3111 F499  795E 2958 4D9F 4086 4578"
          # Security Mailing List
          "F554 A368 7412 CFFE BDEF  E0A3 12F5 F7B4 2F2B 01E7"
        ];
        inherit (src) urls outputHash outputHashAlgo;
      };
    };
  
    meta = with lib; {
      description = "A robust and highly flexible tunneling application";
      homepage = http://openvpn.net/;
      license = licenses.gpl2;
  