Bug 499077

Summary:	KCM needs to be reloaded after adding/removing a printer
Product:	[Applications] systemsettings	Reporter:	Elias Probst <mail>
Component:	kcm_printer_manager	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	noeerover
Priority:	NOR
Version First Reported In:	6.2.90
Target Milestone:	---
Platform:	NixOS
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Elias Probst 2025-01-23 22:34:05 UTC

SUMMARY
When adding/removing a printer, the KCM needs to be reloaded to reflect the change.

STEPS TO REPRODUCE
1. Open printers KCM in System Settings
2. Add or remove a printer
3. Check the list of configured printers

OBSERVED RESULT
The list of configured printers didn't change.
One has to click on another KCM in System Settings first, then back to the printers KCM to show the changes (deleted/added printer).

EXPECTED RESULT
The list of configured printers should update immediately after adding/removing a printer, without having to reload the KCM.

SOFTWARE/OS VERSIONS
Operating System: NixOS 25.05
KDE Plasma Version: 6.2.90
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.1
Kernel Version: 6.6.71 (64-bit)
Graphics Platform: Wayland
Processors: 8 × 11th Gen Intel® Core™ i7-1165G7 @ 2.80GHz
Memory: 31.1 GiB of RAM
Graphics Processor: Mesa Intel® Iris® Xe Graphics

cupsd: 2.4.11
cups-browsed: 2.1.1

ADDITIONAL INFORMATION
All printers I can add/remove are network printers, I don't know whether this applies in the same way for locally USB-connected printers.

Comment 1 Elias Probst 2025-01-23 22:50:02 UTC

It looks like this could be potentially be addressed by https://invent.kde.org/plasma/print-manager/-/merge_requests/215:

> Use cupsEnumDests to get printers. This is the recommended api for moving away from the deprecated CUPS apis that will be removed in CUPS 3.x.

Comment 2 Mike 2025-01-23 22:52:38 UTC

I can't reproduce this.  My gut feeling is that https://invent.kde.org/plasma/print-manager/-/merge_requests/202 is possibly an issue on certain configs.

If you run `systemctl status cups`, do you see something like this in the status:

CGroup: /system.slice/system-cups.slice/cups.service
             ├─ 1279 /usr/sbin/cupsd -l
             ├─32830 /usr/lib/cups/notifier/dbus dbus://
             └─32831 /usr/lib/cups/notifier/dbus dbus://

Comment 3 Mike 2025-01-23 23:13:56 UTC

Can you tell if your NixOS install has CUPS built with HAVE_DBUS?

Comment 4 Mike 2025-01-24 13:06:33 UTC

I've tested with master, 6.3 branch, and with a couple of the new MRs and I can't reproduce this.  Is there anything special or custom about your NixOS build?

Comment 5 Bug Janitor Service 2025-02-08 03:47:24 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 6 Bug Janitor Service 2025-02-23 03:46:53 UTC

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