https://bugs.kde.org/show_bug.cgi?id=513673
Bug ID: 513673
Summary: Plasmashell crashes attempting screencast on stale
window IDs from PipeWire sessions
Classification: Plasma
Product: plasmashell
Version First master
Reported In:
Platform: Arch Linux
OS: Linux
Status: REPORTED
Severity: crash
Priority: NOR
Component: Task Manager and Icons-Only Task Manager widgets
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected]
Target Milestone: 1.0
Created attachment 187856
--> https://bugs.kde.org/attachment.cgi?id=187856&action=edit
the right obs instance shows the bug, where the recording freezes as soon as I
hover over a taskbar icon widget
SUMMARY
Plasmashell crashes when attempting to create screencast thumbnails for stale
window IDs from closed PipeWire sessions. With "Show tooltips" enabled in task
manager, hovering over taskbar icons triggers crash. With tooltips disabled,
OBS recording freezes instead.
STEPS TO REPRODUCE
1. Start OBS with PipeWire screen capture source (Screen1)
2. Close OBS (leaves stale PipeWire screencast session/window ID)
3. Start new OBS instance or reuse existing OBS scene with same Screen1 source
4. Start recording in OBS
5. Hover mouse over taskbar icons in task manager widget
OBSERVED RESULT
**With "Show tooltips" enabled:**
- Plasmashell logs: `error creating screencast "Could not find window id
{UUID}"`
- Plasmashell crashes (segfault, signal 11)
- DrKonqi crash handler appears
- Plasmashell auto-restarts but stale window ID persists
- Crash repeats on subsequent hovers
**With "Show tooltips" disabled:**
- No plasmashell crash
- PipeWire stream in OBS changes state from "streaming" to "paused" after
~10-15 seconds
- OBS recording freezes (no new frames captured)
- journalctl shows: `[pipewire] Stream 0x... state: "paused" (error: none)`
- Requires OBS restart to resume recording
**Key observation:**
The stale window UUID persists across plasmashell restarts. In my testing, UUID
`{d0df4bc8-e137-4a44-b342-708029333b2d}` appeared repeatedly in logs even after
multiple plasmashell crashes/restarts.
EXPECTED RESULT
- Plasmashell should handle missing/stale window IDs gracefully without
crashing
- Closed PipeWire screencast sessions should be cleaned up properly
- Task manager tooltips should skip preview generation for non-existent windows
- Active OBS recordings should not freeze due to unrelated screencast errors
SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux, Kernel 6.17.9-arch1-1
KDE Plasma Version: 6.5.4
KDE Frameworks Version: (run `kinfo` if available)
Qt Version: 6.10.1
GPU: NVIDIA GeForce RTX 3090, Driver 580.105.08
Session: Wayland
OBS Version: 32.0.2
PipeWire Version: 1.4.9
ADDITIONAL INFORMATION
- Video recording attached showing two OBS instances side-by-side:
- **Right instance (old):** Contains "Screen1" source copied from previous
scenes - bug reproduces consistently
- **Left instance (new/fresh):** Newly created Screen1 source - bug does NOT
happen with tooltips disabled, but DOES crash with tooltips enabled
- This suggests the stale window reference is embedded in OBS scene data or
PipeWire session state
- Clearing PipeWire state (`rm -rf ~/.local/state/wireplumber/*`) and
restarting services does NOT fix the issue
- The issue does not occur on X11 sessions (Wayland-specific)
- Related to bugs #480313 and #478518 (similar "Could not find window id"
screencast errors)
**Logs excerpt:**
Dec 21 20:16:20 devwhite obs[117638]: info: [pipewire] Stream 0x... state:
"paused" (error: none) Dec 21 20:16:20 devwhite plasmashell[111982]: error
creating screencast "Could not find window id
{d0df4bc8-e137-4a44-b342-708029333b2d}" Dec 21 20:17:01 devwhite
plasmashell[111982]: KCrash: Application 'plasmashell' crashing...
crashRecursionCounter = 2 Dec 21 20:17:01 devwhite systemd[4716]:
plasma-plasmashell.service: Main process exited, code=dumped, status=11/SEGV
^ completely ai generated text but I had these problems for months now, a
solution is to only use window captures or not hover the taskbar icons at all
which is not really a solution
--
You are receiving this mail because:
You are watching all bug changes.
