Bug 507312

Summary:	Session crashes when repeatedly toggling activity switcher
Product:	[Plasma] kwin	Reporter:	Tech-Tac <im.tech.tac>
Component:	activities	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	crash	CC:	kdedev
Priority:	NOR
Version First Reported In:	6.4.3
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Tech-Tac 2025-07-21 14:09:03 UTC

SUMMARY
Holding down the keyboard shortcut assigned to opening the Activity switcher (Meta+Q by default) causes KWin and the rest of the session to immediately crash.

STEPS TO REPRODUCE
1. Hold down the shortcut for "Show Activity Switcher

OBSERVED RESULT
Session crashes and restarts prompting to report the crash.

EXPECTED RESULT
No crashes.

SOFTWARE/OS VERSIONS
Linux: Arch
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION
Assumes key repeat in keyboard settings is on (which is by default on most distros).
My key repeat settings are as follows:
Status: on, delay: 500ms, rate: 33 repeats/s
I have two activities present.
This however does *not* occur when switching activities, which also shows the switcher briefly.

Unrelated to this bug, but the recent change of making the activity switcher cover the panel seems to be having a regression where it doesn't do so consistently if not always.

Comment 1 TraceyC 2025-07-25 01:35:49 UTC

As the message at the top of the summary says, 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 Tech-Tac 2025-07-29 13:55:42 UTC

(In reply to TraceyC from comment #1)
> As the message at the top of the summary says, 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.

<pre>
(gdb) bt
#0  0x00007f1ca56a574c in ??? () at /usr/lib/libc.so.6
#1  0x00007f1ca564bdc0 in raise () at /usr/lib/libc.so.6
#2  0x00007f1ca900de97 in KCrash::defaultCrashHandler(int) () at /usr/lib/libKF6Crash.so.6
#3  0x00007f1ca564bef0 in <signal handler called> () at /usr/lib/libc.so.6
#4  0x00007f1ca8784e74 in KWin::Compositor::composite(KWin::RenderLoop*) () at /usr/lib/libkwin.so.6
#5  0x00007f1ca5dd37ef in ??? () at /usr/lib/libQt6Core.so.6
#6  0x00007f1ca879e83b in KWin::RenderLoop::frameRequested(KWin::RenderLoop*) () at /usr/lib/libkwin.so.6
#7  0x00007f1ca5dd37ef in ??? () at /usr/lib/libQt6Core.so.6
#8  0x00007f1ca5de0abf in QTimer::timerEvent(QTimerEvent*) () at /usr/lib/libQt6Core.so.6
#9  0x00007f1ca5dc0dd6 in QObject::event(QEvent*) () at /usr/lib/libQt6Core.so.6
#10 0x00007f1ca7101c70 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt6Widgets.so.6
#11 0x00007f1ca5d68118 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt6Core.so.6
#12 0x00007f1ca5f1bc6f in QTimerInfoList::activateTimers() () at /usr/lib/libQt6Core.so.6
#13 0x00007f1ca5f27129 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
at /usr/lib/libQt6Core.so.6
#14 0x00007f1ca6b1ad33 in QUnixEventDispatcherQPA::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
at /usr/lib/libQt6Gui.so.6
#15 0x00007f1ca5d744b6 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt6Core.so.6
#16 0x00007f1ca5d6c7c1 in QCoreApplication::exec() () at /usr/lib/libQt6Core.so.6
#17 0x0000556d1b1c6d16 in ??? ()
#18 0x00007f1ca56356b5 in ??? () at /usr/lib/libc.so.6
#19 0x00007f1ca5635769 in __libc_start_main () at /usr/lib/libc.so.6
#20 0x0000556d1b1cd2b5 in ??? ()
</pre>

Comment 3 TraceyC 2025-07-29 19:58:32 UTC

Thanks for the backtrace. Unfortunately it'ss incomplete and missing debug symbols for the following lines that we need to figure out exactly what's going wrong:

#5  0x00007f1ca5dd37ef in ??? () at /usr/lib/libQt6Core.so.6

Could you please install debug symbols and attach a new symbolicated backtrace generated by using `coredumpctl gdb` in a terminal window? See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Install_debugging_packages for details about how to do this. Then set this back to REPORTED.

Thanks again!

Comment 4 Bug Janitor Service 2025-08-13 03:46:15 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 5 Bug Janitor Service 2025-08-28 03:47:47 UTC

🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.