Comment 8 for bug 1654600

Hello,

This logic is correct. apt_pkg.get_lock(options.lock_file) is trying to acquire a lockfile (/var/run/unattended-upgrades.lock) which is only possible if no unattended-upgrade is already running. If it can acquire the lock, it means that NO unattended-upgrade is running, hence shutdown may proceed.

 while True:
        res = apt_pkg.get_lock(options.lock_file)
        logging.debug("get_lock returned %i" % res)
        # exit here if there is no lock
        if res > 0:
            logging.debug("lock not taken")
            break
        lock_was_taken = True

The problem is that apt_pkg.get_lock(options.lock_file) will also return -1 if the path to the lock file doesn't exist, which is the case when /var is unmounted, hence /var/run is no longer present (/var/run is a symlink to /run).

I'm working on identifying the proper systemd order to make sure that /var/run is still accessible.