I had no problem like this until Plasma 5.18. My Apple Magic Trackpad 2 is connected via Bluetooth, I’ve tried with USB connection too and this way it is unaffected. Must be something with Bluetooth. STEPS TO REPRODUCE 1. Login, click Magic Trackpad 2 to wake up & connect 2. Plasma loads – you can move the cursor now with the trackpad – desktop background loads, then the session is crashing 3. Back to login. The Trackpad is still awake and connected, a new login now works without session crash. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Arch KDE Plasma Version: 5.18.0 KDE Frameworks Version: 5.67.0 Qt Version: 5.4.4 Doesn’t occur when I’m activating the Trackpad a couple seconds after a 'cold' login. But does happen when I’m activating it right after the login splash in a completely loaded desktop. I will offer any log I can provide, just tell me what you need and where I can get it.
Now, it happens even most of the times when I let several minutes past after a login and only then activate the connection. So, I’m changing the title to make this clearer, it doesn’t seems to be related to login.
Needs a backtrace or else there's not much we can do.
How can I create a backtrace log?
Ah, probably classical dmesg output, right? Strangely, after the recent Arch updates, this problem is solved for me now. If it happens again, I will reopen this bug.