Bug 506487

Summary:	KWin 6.4.1 crashes regularly every few hours (seems to happen when triggering hot corner with overview pane), 6.3.x was fine
Product:	[Plasma] kwin	Reporter:	Ellie <el>
Component:	generic-crash	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	crash	CC:	sitter
Priority:	NOR
Version First Reported In:	6.4.1
Target Milestone:	---
Platform:	postmarketOS
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Ellie 2025-07-02 12:33:53 UTC

SUMMARY

KWin 6.4.1 crashes regularly every few hours on the Raspberry Pi 5 I use it on. It seems to happen when triggering hot corner, which I've set to show the overview pane presenting all the windows and showing the workspace switcher at the top. 6.3.x was fine with the same setup, I don't think I changed any part of the configuration other than upgrading to 6.4.1 a few days ago.

Sorry if this issue is already known.

STEPS TO REPRODUCE

1. Configure top-left hot corner to trigger windows overview
2. Use top-left corner a lot with a physical mouse, by moving the cursor into the corner

OBSERVED RESULT

Eventually, kwin will crash. It shows a black screen with a text cursor in the top-left corner. TTY is inaccesible at this point, and the text cursor curiously is permanently visible rather than blinking. The system might otherwise still be alive, I don't think it's a kernel issue.

EXPECTED RESULT

KWin doesn't crash after a few hours.

SOFTWARE/OS VERSIONS

Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: postmarketOS edge based on Alpine edge
KDE Plasma Version: 6.4.1
KDE Frameworks Version: 6.15.0 
Qt Version: 6.8.3

ADDITIONAL INFORMATION

Comment 1 Harald Sitter 2025-07-02 12:58:11 UTC

If something crashed, we need a backtrace of it so we can figure out what's going on. Can you please attach a backtrace of the crash using the coredumpctl command-line program, as detailed in https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl?
Thanks!

Comment 2 Ellie 2025-07-02 13:09:04 UTC

Sorry to make this more complicated, but I don't think postmarketOS or Alpine have coredumpctl, at least not with OpenRC installs. I might get a chance to attach gdb over ssh and leave that running for a while, and see if that yields anything useful. Meanwhile, perhaps somebody else hits this issue as well (it seems to be moderately frequent, multiple times a day) who has access to coredumpctl.

Comment 3 Bug Janitor Service 2025-07-17 03:47:29 UTC

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

Thank you for helping us make KDE software even better for everyone!

Comment 4 Ellie 2025-07-17 07:29:35 UTC

I actually haven't seen this crash for a while now. I suspect it might have been fixed with 6.4.2 or with the Qt update Alpine recently shipped. I will close this ticket for now, if that's okay. If somebody still sees this, feel free to reopen.