Comment 1 for bug 1584456

Thanks for the bug report. We've discussed this on IRC and in a private email thread. I'll summarize here:

"Basically the launcher wants to mount /dev/pts/ptmx on /dev/ptmx and there are
apparmor rules in the launcher's apparmor profile that allow that. However, the
denial is for 'name="/dev/ptmx/"' -- notice the trailing '/' in /dev/ptmx/ --
this is not allowed by the launcher's profile and /dev/ptmx should be a file,
not a directory. From 'man pts': "The file /dev/ptmx is a character file with
major number 5 and minor number 2, ...".

There appears to be a problem with your system, perhaps udev rules. How are your
/dev/ptmx and /dev/pts being setup before any snaps are run (including snaps
with daemons started by systemd)? Are you using a custom kernel, gadget and/or
os snap?"

Can you provide the following:
1. uninstall all app snaps, reboot then provide the output of 'ls -lR /dev/ptmx /dev/pts'
2. 'snap install hello-world' and then run 'hello-world.echo foo', then provide the output of 'ls -lR /dev/ptmx /dev/pts'
3. What kernel snap are you using? If custom, can you attach it?
4. What gadget snap are you using? If custom, can you attach it?
5. What device are you targeting? (eg, amd64 VM, rpi2, rpi3, etc)

Thanks!