Unsure which package upgrade has caused docker daemon startup to fail.
Looks like problem is with configuring the network:
2024-07-22T13:52:48.311618+02:00 host firewalld[1364]: ERROR: NAME_CONFLICT: new_policy_object(): 'docker-forwarding'
2024-07-22T13:52:48.434089+02:00 host firewalld[1364]: WARNING: COMMAND_FAILED: '/usr/sbin/iptables -w10 -t nat -D OUTPUT -m addrtype --dst-type LOCAL -j DOCKER' failed: iptables: Bad rule (does a matching rule exist in that chain?).
2024-07-22T13:52:48.441243+02:00 host firewalld[1364]: WARNING: COMMAND_FAILED: '/usr/sbin/iptables -w10 -t nat -D PREROUTING' failed: iptables: Bad rule (does a matching rule exist in that chain?).
2024-07-22T13:52:48.448046+02:00 host firewalld[1364]: WARNING: COMMAND_FAILED: '/usr/sbin/iptables -w10 -t nat -D OUTPUT' failed: iptables: Bad rule (does a matching rule exist in that chain?).
Relevant full excerpt from syslog: gist
Docker installed from docker apt repo.
Running debian testing.
$ uname -a
Linux p14s 6.9.9-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.9.9-1 (2024-07-13) x86_64 GNU/Linux\
docker-ce & docker-ce-cli 5:27.1.0-1
containerd.io 1.7.19-1
Edit: for future googlers, cause seems to be github com / firewalld/firewalld/issues/1366