up2date: The package .. is signed, but with an unknown GPG key.

After attempting to install libevent-devel on one of our cluster nodes, up2date started complaining about missing GPG signatures. We use the Fedora EPEL repository for fairly new items, and apparently the key were missing / not updated.

The error messages:

warning: rpmts_HdrFromFdno: V3 DSA signature: NOKEY, key ID 217521f6
The package .. is signed, but with an unknown GPG key. Aborting...
Package .. has a unknown GPG signature. Aborting...

The fix for us was to download the keys from Fedora’s key page (we just needed the EPEL-key), and add them with rpm:

wget https://fedoraproject.org/static/217521F6.txt
rpm --import 217521F6.txt 

.. and things worked as it should yet again – and we still get our packages verified. You can also confirm that the key id from the error message (217521F6) is the same as the key that you’ve downloaded from Fedora (or if you’re using another repository they’ll probably provide their keys as well).