Note that these are not actually denials (notice “ALLOWED” in the output), the are violations against policy. Right now, your snap is in devmode, so policy violations are logged, but not denied. If your snap is put in ‘strict’ mode, then these would turn into denials and you would see DENIED instead of ALLOWED.
Some comments on the violations:
- /usr/share/applications/ are usually harmless. If you ‘plugs: [ unity7 ]’ (and connect the interface), this will go away
- the /dev/dri/card0 denial will likely break your snap in strict mode. You need to ‘plugs: opengl ]’ (and connect the interface)
- the /run/udev/data denial is likely harmless, but is solved when you ‘plugs: [ opengl ]’ (and connect the interface)
All that said, the above has nothing to do with /dev/ttyUSB0-- that is a different issue entirely. Looking at the violations it seems like you are running the snap as non-root. I suspect your user does not have the traditional permissions to access /dev/ttyUSB0. You can check this with ‘ls -l /dev/ttyUSB0’ and verifying the permissions on the device. If this is the case, you may want to keep an eye on Multiple users and groups in snaps.