Comment 14 for bug 1873004

The system key is only rewritten if this is required. Normally it is not modified.

The question now is: what has changed that made the system key differ?

One thing we did observe was /snap/core/$current changing without a complete snapd re-start. Perhaps something was pinging snapd over the API and it failed to complete a restart after a core refresh?

Can you check with "snap changes" if there was a corresponding refresh of "core" or "snapd" sometime earlier than the system-key rewrite and in close proximity to the moment LXD started hanging?

System key contains interesting details of the system including build IDs of "snapd", some kernel and userspace library features. One other possibility is update of seccomp or apparmor that might have happened. Is "/usr/lib/snapd/snap-seccomp" and "/snap/core/current/usr/lib/snapd/snap-seccomp" linked statically on s390x?