I installed 26.04 on one of my Incus hosts yesterday. In some LXC instances (running 24.04.4) I’m seeing a problem I remember we saw with earlier Ubuntu releases, where apt update hangs even though other networking works fine. If the instance is privileged, then apt works. This was related to AppAr…

I’ve done a lot more digging. The root cause seems to be that from 25.04 onwards Canonical has been enforcing AppArmor Profile Stacking (/sys/kernel/security/apparmor/features/domain/stack = yes) so we see other things breaking elsewhere too (eg AppArmor: signal rule does not match stacked profile …

Issues in Ubuntu 26.04 - apt not working in unprivileged LXCs

Incus

hereisjames (James) April 24, 2026, 6:00pm 6

Seems very similar to the issues we had with Noble, so I’d guess the fix is the same :

1 Like