Bug 507604

Summary:	kscreen_backend_launcher is logging every time CTM property changes
Product:	[Plasma] KScreen	Reporter:	Bruno J. <maxijac>
Component:	common	Assignee:	kscreen-bugs-null <kscreen-bugs-null>
Status:	RESOLVED NOT A BUG
Severity:	normal	CC:	kde
Priority:	NOR
Version First Reported In:	6.4.3
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Bruno J. 2025-07-28 17:18:49 UTC

SUMMARY

Hello,

I have my own custom script that manages the CTM property of my RandR outputs and applies new values periodically. The problem is that my journal is now spammed by kscreen_backend_launcher which reports on that property every time it changes.


STEPS TO REPRODUCE
1. Have kscreen_backend_launcher running (normal plasma setup)
2. Modify CTM from outside of KDE, using xrandr like with xrandr --set CTM "..."
3. open journalctl and observe the log spam

OBSERVED RESULT

Excerpt of what I see:
```
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Timestamp:  50118684
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Output:  82
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Property:  "CTM"
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         State (newValue, Deleted):  0
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Timestamp:  50118684
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Output:  82
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Property:  "CTM"
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         State (newValue, Deleted):  0
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Timestamp:  50118694
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Output:  83
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Property:  "CTM"
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         State (newValue, Deleted):  0
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Timestamp:  50118694
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Output:  83
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Property:  "CTM"
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         State (newValue, Deleted):  0
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper: RRNotify_OutputProperty (ignored)
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Timestamp:  50118709
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Output:  82
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         Property:  "CTM"
juil. 19 22:49:18 fixe kscreen_backend_launcher[1260]: kscreen.xcb.helper:         State (newValue, Deleted):  0
```

EXPECTED RESULT
No logged data

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

ADDITIONAL INFORMATION
Maybe if I could find a way to disable kscreen alone it would be a nice temporary workaround, but I could not find a way to disable this service alone?

Comment 1 David Redondo 2025-07-29 09:59:53 UTC

You can disable it in ~/.config/QtProject/qtlogging.ini     
https://doc.qt.io/qt-6/qloggingcategory.html#logging-rules