How to fix dpkg: warning: unable to delete old directory '/path': Directory not empty in APT

This warning is generally not a problem and does not prevent your package operation from completing. dpkg has already removed the package files successfully; it simply couldn't delete the directory because it's not empty. The warning is informational rather than critical. You can safely continue using your system and the package.

If you want to investigate what's left in the directory, use ls to view its contents. Replace /path with the actual directory from the warning message:

ls -la /path

This will show you what files or subdirectories are still present. If the directory is empty but the warning still occurred, the issue may have already resolved itself.

If you're removing a package and want to ensure all configuration files and related directories are cleaned up, use purge instead of remove:

sudo apt purge package-name

Purge removes both the package and all associated configuration files. Use apt purge after apt remove on packages you're no longer using:

sudo apt remove package-name
sudo apt purge package-name

This is more thorough than remove alone but may still not delete directories if they contain other non-owned files.

If you've verified that the leftover directory contains only orphaned files and nothing important, you can manually remove it. First, verify the directory is safe to delete by checking its contents:

sudo ls -la /path

If the directory is empty or contains only files you don't need:

sudo rmdir /path

For directories with contents, use:

sudo rm -rf /path

Be extremely careful with rm -rf as it irreversibly deletes files. Only use this on directories you fully understand and can verify are safe to remove.

Run the apt cleaning commands to remove unused dependencies and temporary files:

sudo apt autoremove
sudo apt autoclean

apt autoremove removes packages that were automatically installed but are no longer needed by any installed package. apt autoclean clears the apt package cache of old package files. These won't directly fix directory cleanup but help maintain a clean system.

List all packages that have been removed but not purged (marked as "rc" in dpkg):

dpkg --list | grep '~rc'

To purge all remaining unpurged packages at once:

sudo apt purge ~c

Or purge specific unpurged packages:

sudo apt purge package-name

This removes configuration files and may clean up orphaned directories that weren't handled during the initial removal.