Comment #5 : Bug #1988119 : Bugs : systemd package : Ubuntu

I've removed the update from bionic-security and bionic-updates, and restored the versions which were previously in there. This won't help anyone that has already received the broken update - I think the advice there is to restart, or there is a workaround in the OP here - but it should prevent any further occurrences. Note that there will be a delay of up to an hour or so for mirrors to receive the deletion.