Unknown syscall when running an 18.04 built snap

This is likely it trying to handle itself crashing.

This rule is missing from desktop-legacy:

dbus (send)
    bus=session
    path=/org/a11y/bus
    interface=org.freedesktop.DBus.Properties
    member="Get{,All}"
    peer=(label=unconfined),

(there are another Get rule, but it doesn’t match the above). I’ll add that to the next batch of updates.