How to fix dpkg: unrecoverable fatal error, aborting: triggers looping, abandoned in APT

First, attempt to finish any incomplete package operations that may have caused the trigger loop:

sudo dpkg --configure -a

This tells dpkg to configure all packages that are only half-installed or unpacked.

If dpkg configuration alone doesn't work, use apt to fix broken packages:

sudo apt-get install -f

The -f (--fix-broken) flag installs missing dependencies and removes conflicting packages.

If the error persists, stale lock files may be blocking resolution. Remove them:

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

Be cautious only to run this when apt/dpkg is NOT running. Then retry configuration.

For persistent trigger loop issues, you may need to clear the triggers processing state:

sudo rm /var/lib/dpkg/triggers/Lock
sudo dpkg --configure --pending

This removes the lock and reruns pending triggers configuration from scratch.

Once dpkg returns to a consistent state, verify integrity and resume system updates:

sudo apt-get update
sudo apt-get upgrade

Monitor the output for any remaining errors. If they recur, note the specific package names mentioned in the error chain for further investigation.