Comment 23 for bug 1693361

Since 20.04, apt can wait for a lock.

The apt(8) command automatically waits for a lock for 120 seconds (non-interactive) or infinitely.

The apt-get(8) command can be configured to wait as well by passing the -o DPkg::Lock::Timeout=<number of seconds>, where <number of seconds> may also be -1 for infinite.

This avoids any races you'd get by doing the lock yourself and then invoking apt.