Comment 11 for bug 1773515

This has also bugged me for some number of months but the work around is really easy -- just use
apt purge snapd
instead of
apt remove snapd

What happens is that upon removal of the snapd package, dpkg sees that /var/lib/snapd/apparmor/snap-confine is empty and removes it which later breaks apparmor when it tries to open that directory (as referenced by /etc/apparmor.d/usr.lib.snapd.snap-confine.real at line 11 which the log clearly states).

Since usr.lib.snapd.snap-confine.real is a configuration file it does not get removed during `apt remove`