apt-get%20install%20git%20E:%20Could%20not%20open%20lock%20file%20/var/lib/dpkg/lock-frontend%20-%20open%20(13:%20Permission%20denied code example

Example 1: dpkg: error: dpkg frontend lock was locked by another process with pid 4368

sudo rm /var/lib/dpkg/lock-frontend
sudo dpkg --configure -a

Example 2: E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

sudo kill -9 PID
sudo rm /var/lib/dpkg/lock-frontend
sudo apt update

Example 3: 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.