Bug 502828

Summary: With KNewStuff backend loaded, Discover fails to fully exit on quit, causing it to not launch again
Product: [Applications] Discover Reporter: Alpha-Craft <knolld00>
Component: KNewStuff BackendAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED FIXED    
Severity: major CC: aleixpol, john.kizer, leinir, nate, sitter
Priority: NOR    
Version First Reported In: 6.3.4   
Target Milestone: ---   
Platform: Fedora RPMs   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Alpha-Craft 2025-04-15 10:24:39 UTC
SUMMARY
Discover will open the first time I do in a session. After that, there is a process running in the background. If I try opening Discover again later, it will refuse to open until I kill that process or any other potentially spawned process.

STEPS TO REPRODUCE
1. Open Discover for the first time in a Plasma session
2. Close it
3. Try to reopen
4. Kill/quit discover process
5. Open Discover again

OBSERVED RESULT
Discover doesn't launch another time after the first launch in a session unless the background process is killed.

EXPECTED RESULT
Discover should normally launch after it has been quit previously in the same Plasma session.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Fedora 41 KDE
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.13.0
Qt Version: 6.8.2

ADDITIONAL INFORMATION
None
Comment 1 Nate Graham 2025-04-16 17:05:06 UTC
Is this 100% reproducible, including when you run `plasma-discover` in a terminal window and then quit it by clicking its close button?

If so, let's go backend by backend and see which one is hanging on quit. Run `plasma-discover --listbackends`. It will spit out something like this:

Available backends:
 * fwupd-backend
 * flatpak-backend
 * packagekit-backend
 * kns-backend

Then please open Discover with one backend at a time with `plasma-discover --backends [the backend name]` e.g `plasma-discover kns-backend`. Then quit by clicking on the close button.

Ideally one of them will hang on close and we'll be able to know which one it is!
Comment 2 Alpha-Craft 2025-04-17 10:50:02 UTC
(In reply to Nate Graham from comment #1)
> Is this 100% reproducible, including when you run `plasma-discover` in a
> terminal window and then quit it by clicking its close button?
> 
> If so, let's go backend by backend and see which one is hanging on quit. Run
> `plasma-discover --listbackends`. It will spit out something like this:
> 
> Available backends:
>  * fwupd-backend
>  * flatpak-backend
>  * packagekit-backend
>  * kns-backend
> 
> Then please open Discover with one backend at a time with `plasma-discover
> --backends [the backend name]` e.g `plasma-discover kns-backend`. Then quit
> by clicking on the close button.
> 
> Ideally one of them will hang on close and we'll be able to know which one
> it is!

I have done the testing and for one, it also happens when I am launching it via the terminal with `plasma-discover`. I also tested the individual backends, and the single one backend that appears to hang is the *kns-backend*. Everything else worked just fine.
Comment 3 Nate Graham 2025-04-17 16:58:45 UTC
Thanks. I had a feeling it was going to be KNS. Disappointing to hear that it's still happening in Plasma 6.3.4 with Frameworks 6.13; I had thought we squashed this bug.

@sitter another notch in favor of deleting KNS functionality entirely...
Comment 4 John Kizer 2025-04-20 21:14:35 UTC
Interestingly, with the system below, I can't reproduce this - just to check, are you still able to reproduce after the latest updates, including the Qt 6.9 ones?

Thanks!

Operating System: Fedora Linux 42
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.13.0
Qt Version: 6.9.0
Kernel Version: 6.14.2-300.fc42.x86_64 (64-bit)
Comment 5 Bug Janitor Service 2025-05-05 03:47:09 UTC
๐Ÿ›๐Ÿงน โš ๏ธ 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 2025-05-20 03:47:10 UTC
๐Ÿ›๐Ÿงน This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.
Comment 7 Alpha-Craft 2025-05-23 10:17:14 UTC
This is still hapenning. I need to check whether there are updates to QT and I am planning to upgrade from Fedora KDE 41 to version 42 very soon.
Comment 8 Nate Graham 2025-05-23 20:40:08 UTC
OK, let us know!
Comment 9 Alpha-Craft 2025-05-24 17:29:55 UTC
(In reply to Nate Graham from comment #8)
> OK, let us know!

I upgraded my installation today and have QT 6.9. The issue still persists.
Comment 10 Alpha-Craft 2025-06-21 08:52:23 UTC
This bug has been fixed with Plasma 6.4. Closing.