How to fix The following packages have unmet dependencies in APT

Start by refreshing your package lists to ensure apt has current information about available packages and versions:

sudo apt update

This fetches the latest package metadata from your configured repositories. After running this, try your installation again, as the issue may have been caused by stale cache.

Upgrade your currently installed packages to their latest compatible versions, then attempt to fix any broken dependencies:

sudo apt upgrade
sudo apt --fix-broken install

The --fix-broken option tells apt to resolve dependency issues by removing conflicting packages if necessary. This often resolves unmet dependencies caused by partial upgrades.

If regular upgrade does not work, use dist-upgrade, which performs a more aggressive upgrade and is better at resolving dependency conflicts:

sudo apt dist-upgrade

Note that dist-upgrade may remove packages to resolve conflicts, so review the output carefully before confirming. For production systems, test this on a non-critical environment first.

Held packages prevent apt from modifying them to resolve dependencies. List any held packages:

apt-mark showhold

If you see packages listed, consider unholding them temporarily to allow apt to resolve dependencies:

sudo apt-mark unhold <package-name>

After resolving the dependency issue, you can hold the package again if desired.

If the above steps fail, you may need to remove the conflicting package. First, simulate the removal with a dry-run to see what would be removed:

sudo apt remove --dry-run <package-name>

If the output looks safe, proceed with the actual removal:

sudo apt remove <package-name>

Then try installing the package you originally wanted.

As a nuclear option, clear the apt cache and reinstall the problematic package:

sudo apt clean
sudo apt autoclean
sudo apt install --reinstall <package-name>

This removes all cached package files and forces apt to re-download and verify them. Use this only after other solutions have failed, as it forces a fresh installation of the entire package and its dependencies.

If the error persists, check if you have third-party PPAs that provide conflicting packages:

ls /etc/apt/sources.list.d/

Disable or remove problematic PPAs by renaming their files or removing them entirely:

sudo mv /etc/apt/sources.list.d/problematic-ppa.list /etc/apt/sources.list.d/problematic-ppa.list.bak
sudo apt update

Then try your installation again. PPAs from different maintainers often have conflicting package versions.