How to fix zincati not updating CoreOS: rpm-ostree deploy failed: error: Packages not found: ...

Problem:

My zincati service - the service that automatically updates CoreOS could not update CoreOS due to the following logs (view with journalctl -xfu zincati.service):

[ERROR zincati::update_agent::actor] failed to stage deployment: rpm-ostree deploy failed:
    error: Packages not found: magic-wormhole

Solution

The solution typically involves uninstalling the package - in this case magic-wormhole using

sudo rpm-ostree uninstall magic-wormhole

Note that this might uninstall a service that is required for your infrastructure, and it will delete files associated with the package in the process of uninstalling it. You should make a backup of valuable data in any case.