Running KDE Neon Unstable edition and it’s actually been my favorite distribution I’ve used in a long time.
But I noticed I couldn’t change the brightness on my laptop (ThinkPad T480s) about a week ago after the 6.4 update. Tried updating the nvidia drivers, which didn’t fix it. Looked at it today and was getting an error:
May 22 19:01:05 saturn systemd[1390]: Starting plasma-powerdevil.service - Powerdevil...
May 22 19:01:05 saturn (werdevil)[4017]: plasma-powerdevil.service: **Failed to apply ambient capabilities** (before UID change): Operation not permitted
May 22 19:01:05 saturn systemd[1390]: plasma-powerdevil.service: Main process exited, code=exited, status=218/CAPABILITIES
May 22 19:01:05 saturn systemd[1390]: plasma-powerdevil.service: Failed with result 'exit-code'.
May 22 19:01:05 saturn systemd[1390]: Failed to start plasma-powerdevil.service - Powerdevil.
May 22 19:01:05 saturn systemd[1390]: plasma-powerdevil.service: Scheduled restart job, restart counter is at 5.
May 22 19:01:05 saturn systemd[1390]: plasma-powerdevil.service: Start request repeated too quickly.
May 22 19:01:05 saturn systemd[1390]: plasma-powerdevil.service: Failed with result 'exit-code'.
May 22 19:01:05 saturn systemd[1390]: Failed to start plasma-powerdevil.service - Powerdevil.
I didn’t want to edit the service file directly because I assume it would be overwritten in an update, but it had the line AmbientCapabilities=CAP_WAKE_ALARM, not sure why, but this was definitely my issue.
I created an override file at ~/.config/systemd/user/plasma-powerdevil.service.d/override.conf that simply ammended the ambient capabilities flag to be empty. After a reboot, it seems to have fixed my issue.
I did a search before posting, but couldn’t find anything this specific or even remotely recent. Not sure if anyone else has run into any issues or what may have gone drastically changed on my system to have created the issue suddenly.