Public bug reported: It is possible that the postinst is going to trigger a restart of systemd-binfmt.service. Take a look at this section of systemd.postinst
_update_binfmt() { _systemctl restart systemd-binfmt.service || true } # Update Message Catalogs database and binfmt registrations in response to dpkg triggers if [ "$1" = "triggered" ]; then shift for trigger in $@; do case $trigger in /usr/lib/systemd/catalog) _update_catalog an ;; /usr/lib/binfmt.d) _update_binfmt ;; esac done exit 0 fi It happened to me when I create a Incus Ubuntu noble container from an older image (2024-05-30) and then simply did a "apt update" plus "apt dist-upgrade" in the container. I'm getting Failed to restart systemd-binfmt.service: Unit systemd-binfmt.service is masked. I'm not getting that error when I launch from the latest Incus image. So something might depend on other things. Nevertheless, the postinst should not even try to restart a service that is masked. ** Affects: systemd (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2077869 Title: systemd.postinst wants to restart masked systemd-binfmt.service To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/2077869/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs