This is due to the rpmdb move to sqlite. You need to let Zincati perform the upgrade so that it goes through the 33.20201201.3.0 barrier release.
In general, we need to avoid using rpm-ostree upgrade directly for now and let Zincati do the upgrades (in fact in later releases, this requires an override switch). Barrier releases fix or migrate important bits of the OS.
We’re working on improving the UX there so that e.g. rpm-ostree talks to Zincati, but for now the only supported way to upgrade nodes is through Zincati (and the longer a node has gone without upgrading, the more likely it is to hit barrier-related issues like this).
Thanks for the information.
We have specifically disabled zincati auto updates to avoid sudden reboots of the VMs.
Can I somehow call this manually?
Could I also upgrade to 33.20201201.3.0 explicitly with rpm-ostree? (And then further.)
I tried rpm-ostree -os= but it at least doesn’t accept this version string …
Upgrading the production VMs also worked fine except for that exactly half of the VMs had the /run/systemd/resolv/stub-resolve.conf symlink missing after each upgrade step. But that is easily handled.