/var/lib/dpkg/lock-frontend) code example
Example 1: how to realse the lock in the linux in apt
sudo kill <process_id>
Example 2: why upgrade ubuntu then frequently shows this message "It iwating for cache lock: Could not get lock /var/lib/dpkg/lock.frontend.
It iwating for cache lock: Could not get lock /var/lib/dpkg/lock.frontend.