How to prevent gpg-agent from timing out during passphrase collection?

I'm calling out to gpg2 in a CLI script for symmetrical encryption of a local file. It appears to have gpg-agent prompt for a passphrase via some CLI, text based UI. As long as I'm around to enter the passphrase everything works fine. If I'm not, however, it eventually fails out with this message:

gpg-agent[15338]: command get_passphrase failed: Operation cancelled
gpg: cancelled by user
gpg: error creating passphrase: Operation cancelled
gpg: symmetric encryption of `XXXX.tar' failed: Operation cancelled

Is there any way to turn off this timeout entirely?

I would want the passphrase prompt to remain on the screen indefinitely until I enter something.

Solution 1:

The solution has been found here: https://dev.gnupg.org/T3240

The delay is caused by the pinentry querying the GNOME keyring. Add no-allow-external-cache to your gpg-agent.conf, or remove gnome-keyring, and kill currently running gpg-agent: gpgconf --kill gpg-agent

Solution 2:

In gpg-agent.conf (see gpg-agent(1)), try the following options:

pinentry-timeout 0
pinentry-program /usr/bin/pinentry-curses --timeout 0

(You might find pinentry-tty somewhat nicer to use though.)