anchor.diff: -{ lib, stdenv, fetchurl, pkg-config, udev, dbus, perl, python3
  -, IOKit ? null }:
  +{ lib, stdenv, fetchurl, pkg-config, udev, dbus, perl, python3, IOKit }:
   
   stdenv.mkDerivation rec {
     pname = "pcsclite";
  
positive.code:     "--enable-usbdropdir=/var/lib/pcsc/drivers"
      "--enable-confdir=/etc"
    ] ++ lib.optional stdenv.isLinux
           "--with-systemdsystemunitdir=\${out}/etc/systemd/system"
      ++ lib.optional (!stdenv.isLinux)
           "--disable-libsystemd";
  
    postConfigure = ''
      sed -i -re '/^#define *PCSCLITE_HP_DROPDIR */ {
  
negative.code:   '';
  
    nativeBuildInputs = [ pkg-config perl ];
  
    buildInputs = [ python3 ]
      ++ lib.optionals stdenv.isLinux [ udev dbus ]
      ++ lib.optionals stdenv.isDarwin [ IOKit ];
  
    meta = with lib; {
      description = "Middleware to access a smart card using SCard API (PC/SC)";
  