Slow print windows on Kde plasma on QT application

[totorux]

Hi,

Describe the bug
Slow print windows on Kde plasma, on QT application

On Ubuntu 24.04, I have a problem when I setup BrowseRemoteProtocols to none and or BrowseProtocols to none in cups-browsed.conf file.

To Reproduce
Steps to reproduce the behavior:

1. Edit /etc/cups/cups-browsed.conf file
2. Change "BrowseRemoteProtocols dnssd cups" to "BrowseRemoteProtocols none" or "BrowseProtocols" to "BrowseProtocols none"
   Or
   Change "BrowseRemoteProtocols dnssd cups" to "BrowseRemoteProtocols cups"
3. Open any qt application (kate, okular tested) try to print.
4. The print windows take 2-3 second to appeared.

System Information:

• OS: Ubuntu
• Version : 24.04
• Plasma : 5.27.11

Need to restart OS to take change.

[tillkamppeter]

Does this only occur for KDE/Qt apps or also for other apps (GNOME/GTK, LibreOffice, Mozilla, Chromium)?

If you have this cups-browsed configuration (DNS-SD browsing support turned off) what is the output of lpstat -v and what of lpstat -l -e? How long do these commands need to finish.

Why do you need such a cups-browsed configuration? How and for what are you using cups-browsed with it? Could you attach your cups-browsed.conf.

Could you set cups-browsed.conf to do debug logging into a file and also set CUPS to debug logging (cupsctl --debug-logging and when you open the print dialog of a Qt app again and it again takes time, attach /var/log/cups/error_log and /var/log/*/cups-browsed_log?