Comment # 16 on bug 1217029 from Fabian Vogt

I had a look as well. Meanwhile it's the networkd_init module that fails:
https://openqa.opensuse.org/tests/4194179#step/networkd_init/48

systemd-run -tM node1 /bin/bash -c "zypper lr -u" does not return.

While it appears like zypper got stuck, this is not the case. The zypper
process finishes successfully (visible in logs) and inside the container it
also reports that the run-uNR.service unit finished. So it appears to be the
communication issue indicated by comment 1.