How to fix E: Unattended upgrade returned False in APT

View the detailed error log to understand what failed:

sudo cat /var/log/unattended-upgrades/unattended-upgrades.log

Look for the last few lines that indicate the specific error. Common patterns include "Cache has broken packages" or dependency-related messages.

First, check if packages are being held:

apt-mark showhold

If packages are held, unhold them:

sudo apt-mark unhold <package-name>

Then fix broken dependencies:

sudo apt --fix-broken install
sudo dpkg --configure -a

Run the update and upgrade process manually to test:

sudo apt update
sudo apt upgrade

This allows you to see the actual error messages and confirm whether the issue is resolved. If apt prompts about changes, review and confirm.

Verify available disk space, particularly in / and /var:

df -h

If space is low (less than 10% available), clean up:

sudo apt clean          # Remove all cached .deb files
sudo apt autoclean      # Remove old cached versions only
sudo apt autoremove     # Remove unused dependencies

Check if apt or dpkg is already running:

ps aux | grep -i apt
ps aux | grep -i dpkg

If no processes are shown, safely remove stale lock files:

sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock*

Then retry apt update and upgrade.

After resolving the issues above, manually trigger unattended-upgrades:

sudo unattended-upgrade -d

The -d flag enables debug output. Check for "All packages are up to date" or other success messages. If still failing, the error details will help identify remaining issues.