**Important** The `cache-ttl` options do **NOT** apply when using a YubiKey as a smartcard as the PIN is [cached by the smartcard itself](https://dev.gnupg.org/T3362). Therefore, in order to clear the PIN from cache (smartcard equivalent to `default-cache-ttl` and `max-cache-ttl`), you need to unplug the YubiKey.
**Tip** Set `pinentry-program /usr/bin/pinentry-gnome3` for a GUI-based prompt.
**Tip** Set `pinentry-program /usr/bin/pinentry-gnome3` for a GUI-based prompt.
On macOS, use `brew install pinentry-mac` and adjust the program path to suit.
On macOS, use `brew install pinentry-mac` and adjust the program path to suit.