Comment 13 for bug 1331856

Uhm I get same error even if variable is introduced in /etc/apparmor.d/tunables/:

```
$ cat /etc/apparmor.d/tunables/usr.bin.qtox | head -n1
@{qtox_prefix} = /usr /usr/local
```

Adding local customisation:

```
$ cat /etc/apparmor.d/tunables/usr.bin.qtox.d/local
@{qtox_prefix} += /tmp/qtox
```

I get:

```
$ sudo aa-logprof

ERROR: Values added to a non-existing variable @{qtox_prefix}: /tmp/qtox in tunables/usr.bin.qtox.d/local
```