Bug 408232

Summary:	System settings crashes on startup after changing lock screen appearance
Product:	[Applications] systemsettings	Reporter:	Andrei Rybak <rybak.a.v>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	crash	CC:	nate
Priority:	NOR
Version First Reported In:	5.13.5
Target Milestone:	---
Platform:	Kubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Andrei Rybak 2019-06-03 05:02:42 UTC

SUMMARY
Tried to change lock screen appearance (last action was click on the background color picker). System settings window closed (without crash notification). Subsequent attempts to launch "System settings" failed.

STEPS TO REPRODUCE
1. Do something what systemsettings5 apparently can't handle in the tab "Desktop Behavior > Screen locking > Appearance".
2. "System settings" window closes by itself
3. Try to launch "System settings" again from launcher.
4. "$ systemsettings5"
5. "$ systemsettings5 --version"

OBSERVED RESULT
What seems like a crash on step #2
System settings does not launch on step #3
On step #4:
> Please instantiate the QApplication object first
On step #5:
> Please instantiate the QApplication object first
 and no output about the version

EXPECTED RESULT
"System settings" application does not crash after step #1
"System settings" application launches on steps #3 and #4.
Version info is printed on step #5.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kubuntu 18.10
(available in About System)
KDE Plasma Version: 5.13.5
KDE Frameworks Version: 5.50.0
Qt Version: 5.11.1

Comment 1 Nate Graham 2019-06-05 15:50:43 UTC

Please attach a backtrack of the crash. Thanks!

For more details, see https://community.kde.org/Get_Involved/Bug_Reporting#Crash_reports_must_include_backtraces

Comment 2 Andrei Rybak 2019-06-06 20:38:12 UTC

I'm sorry if I didn't make myself clear in the bug report. This crash was not caught by crash assistant (like Kdenlive crash in my other bug report https://bugs.kde.org/show_bug.cgi?id=407844). Therefore, there is no backtrace that I could provide.

Comment 3 Nate Graham 2019-06-06 20:56:04 UTC

In that case you will need to generate it yourself. See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports

Comment 4 Andrei Rybak 2019-06-08 08:43:51 UTC

Because steps are not reliable, I can not longer reproduce.