apt update var/lib/dpkg/lock-frontend 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 dpkg --configure -a
dpkg: error: parsing file '/var/lib/dpkg/updates/0004' near line 0:
newline in field name '#padding'