How to fix E: The package cache file is corrupted in APT

Remove all corrupted cache files from /var/lib/apt/lists/. This is the fastest and safest solution:

sudo rm -rf /var/lib/apt/lists/*

Warning: Make sure you include the * at the end. Omitting it will delete the entire /var/lib/apt/lists/ directory itself, which may not be recreated.

After clearing, rebuild the cache:

sudo apt update

This will download fresh package metadata from your configured repositories.

If the previous step deleted /var/lib/apt/lists/ entirely (unlikely but possible), recreate the partial subdirectory that apt needs:

sudo mkdir -p /var/lib/apt/lists/partial
sudo chmod 755 /var/lib/apt/lists
sudo apt update

This ensures apt has the necessary directory structure to download fresh metadata.

If clearing the cache doesn't resolve the issue, especially if you see "Structure needs cleaning" errors, your filesystem itself may be corrupted. Check and repair it:

sudo fsck -f /dev/sda1

Replace /dev/sda1 with your actual root partition. You may need to boot into recovery mode or use a live USB for this. After fsck completes, reboot and try apt again.

Note: This is primarily a concern on Raspberry Pi or embedded systems with SD cards. Desktop/server users rarely need this step unless hardware is failing.

Before manually clearing the cache, try apt's built-in cleanup commands, which are safer:

sudo apt clean
sudo apt autoclean
sudo apt update

apt clean removes all package cache files, while apt autoclean removes only old versions. These are reversible operations. If they don't resolve the issue, proceed to the full cache clear above.

After rebuilding the cache, ensure your software sources are valid:

sudo apt-cache search . | head
sudo apt list --upgradable

If you still encounter errors, review your /etc/apt/sources.list and /etc/apt/sources.list.d/ files:

sudo nano /etc/apt/sources.list

Check for duplicate, malformed, or outdated repository entries. Make sure all URLs are correct and your system architecture matches the available packages.

Package cache corruption can indicate underlying hardware problems. Check available disk space:

df -h /var/lib/apt

Ensure you have at least 100MB free. If storage is full or nearly full, delete old packages and temporary files:

sudo apt clean
sudo apt autoclean
sudo journalctl --vacuum=1w

For Raspberry Pi or systems with SD cards, monitor SMART health:

sudo smartctl -a /dev/sda

If you see SMART errors, your storage device may be failing and needs replacement.