Description of problem: RHEL-8 only ships plpython3. RHEL-7 (up to rh-postgresql12) only ships plpython (which is python2). In order to enable customers to be able to upgrade, it seems like the best way forward is to enable both, plpython and plpython3 in rh-postgresql13. That way, customers can move from plpython to plpython3 when still being on rh-postgresql13, and then migrating to RHEL-8. We should document this as well.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (new packages: rh-postgresql13), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2021:2218