Troubleshooting AppArmor problems

I've been here racking my brains for the past several days, trying to come up with a good troubleshooting scenario. It turns out that I didn't need to. The Ubuntu folk have handed me a good scenario on a silver platter in the form of a buggy Samba profile. Now that Ubuntu 18.04 is out, there are two parts to this saga. The first part applies to Ubuntu 16.04, and the second part applies to Ubuntu 18.04.

Troubleshooting an AppArmor profile – Ubuntu 16.04

As you've just seen, I used aa-enforce to put the two Samba-related profiles into enforce mode. But watch what happens now when I try to restart Samba in order to get the profiles to take effect:

donnie@ubuntu3:/etc/apparmor...