anchor.diff: -{ stdenv, fetchurl, fetchpatch, pkgconfig
  +{ stdenv, fetchurl, fetchpatch, pkgconfig, makeWrapper
   , iproute, lzo, openssl, pam
   , useSystemd ? stdenv.isLinux, systemd ? null, utillinux ? null
   , pkcs11Support ? false, pkcs11helper ? null,
  
positive.code:     cp -r sample/sample-config-files/ $out/share/doc/openvpn/examples
      cp -r sample/sample-keys/ $out/share/doc/openvpn/examples
      cp -r sample/sample-scripts/ $out/share/doc/openvpn/examples
  
      ${optionalString useSystemd ''
        install -Dm755 ${update-resolved} $out/libexec/update-systemd-resolved
  
        substituteInPlace $out/libexec/update-systemd-resolved \
          --replace '/usr/bin/env bash' '${stdenv.shell} -e' \
          --replace 'busctl call'       '${getBin systemd}/bin/busctl call' \
          --replace '(ip '              '(${getBin iproute}/bin/ip ' \
          --replace 'logger '           '${getBin utillinux}/bin/logger '
      ''}
    '';
  
    enableParallelBuilding = true;
  
negative.code: with stdenv.lib;
  
  let
    # Check if the script needs to have other binaries wrapped when changing this.
    update-resolved = fetchurl {
      url = "https://raw.githubusercontent.com/jonathanio/update-systemd-resolved/v1.3.0/update-systemd-resolved";
      sha256 = "021qzv1k0zxgv1rmyfpqj3zlzqr28xa7zff1n7vrbjk36ijylpsc";
    };
  
  in stdenv.mkDerivation rec {
  