You need these packages:

  • pcsclite
  • libusb-compat

If you use Gemalto GemPC Key SmartCard Reader aka IDBridge K30 (VID:PID: 08e6:3438) and pcsc_scan returns “SCardEstablishContext: Service not available” that means that pcscd is not running. After starting it gpg –card-status should work.