How to fix dpkg: error: dpkg status database is locked by another process in APT

First, see if there are any active apt processes:

ps aux | grep -i apt

If you see active apt processes, wait for them to finish naturally. If you see only your grep command, proceed to the next step.

Use lsof to find the process holding the lock:

sudo lsof /var/lib/dpkg/lock
sudo lsof /var/lib/dpkg/lock-frontend

Note the PID (Process ID) if one is returned. If no process is listed, the lock file may be stale.

If a process was found, kill it gracefully:

sudo kill PID

Wait a few seconds. If the process doesn't terminate, force kill it:

sudo kill -9 PID

Alternatively, kill all stuck apt processes:

sudo pkill -9 apt
sudo pkill -9 apt-get

Once the blocking process is confirmed stopped, remove the lock files:

sudo rm /var/lib/dpkg/lock
sudo rm /var/lib/dpkg/lock-frontend
sudo rm /var/cache/apt/archives/lock

Warning: Only remove lock files after confirming the blocking process is terminated. Removing them while a process is still running can corrupt your package database.

After removing locks, reconfigure dpkg to finish any pending operations:

sudo dpkg --configure -a

Then update the package list:

sudo apt update

You can now resume normal package operations.

If the above steps don't work, a system reboot will release all locks:

sudo reboot

This is the safest option if you're unsure about process termination. After reboot, dpkg will be in a clean state.