VLC crashes (SIGSEGV) on Raspberry Pi OS Bookworm (Pi 5) during playlist playback — Wayland / dmabuf related

[technomarshal]

I've been running into a reoccurring issue when playing long run playlists on repeat/random play on Bookworm on a Pi5. The VLC player will crash intermittently after completing playback of a playlist entry. Sometimes it's fast, one or 2 videos play, then the app crashes, other times it will run for a good amount of time and then crash. I used ChatGPT to help with debugging and isolated the issue in the report is below and I believe I've found a good workaround for now.

VLC crashes (SIGSEGV) on Raspberry Pi OS Bookworm (Pi 5) during playlist playback — Wayland / dmabuf related
Summary

VLC consistently segfaults (SIGSEGV) on Raspberry Pi OS Bookworm running on Raspberry Pi 5 during playlist playback.
The crash occurs after several media items play successfully, typically during the transition between videos.

A core dump shows the crash occurring inside libwayland-client.so, specifically wl_list_remove(), with active involvement of Wayland dmabuf (libwl_dmabuf_plugin.so) and QtWayland.

Forcing VLC to use X11 (QT_QPA_PLATFORM=xcb) and disabling hardware decoding completely eliminates the crash, strongly suggesting a Wayland + dmabuf lifecycle bug triggered during video output teardown/reinitialization.

Environment

Hardware: Raspberry Pi 5

OS: Raspberry Pi OS Bookworm (64-bit)

Desktop session: Wayland

echo $XDG_SESSION_TYPE
wayland

VLC package: distro VLC (/usr/bin/vlc)

Architecture: aarch64 (ARM64)

Steps to Reproduce

Boot Raspberry Pi OS Bookworm on Raspberry Pi 5

Log into the default Wayland desktop session

Launch VLC normally (GUI)

Load and play an XSPF or M3U playlist containing multiple video files

Allow several videos to play sequentially

During a media transition, VLC abruptly exits

Observed Behavior

VLC terminates unexpectedly

Terminal output (when launched from CLI) shows:

[h264_v4l2m2m] Could not find a valid device
[h264_v4l2m2m] can't configure decoder
Segmentation fault (core dumped)

A core dump is generated

Expected Behavior

VLC should continue playlist playback without crashing, or at minimum fail gracefully without a segmentation fault.

Core Dump / Stack Trace (key excerpt)

From coredumpctl gdb:

Program terminated with signal SIGSEGV, Segmentation fault.
#0 wl_list_remove ()
from /lib/aarch64-linux-gnu/libwayland-client.so.0

Current thread:
Thread 0x7ffe6143f0c0 (LWP 40814)

Stack trace of crashing thread:
#0 wl_list_remove (libwayland-client.so.0)
#1 wl_display_dispatch_queue_pending (libwayland-client.so.0)
#2 libwl_dmabuf_plugin.so
#3 start_thread (libc.so.6)

Other threads show active QtWayland, QtCore, VLC vout teardown, and libavcodec activity at the time of the crash.

This strongly suggests a Wayland object lifecycle / dmabuf teardown issue during video output reinitialization.

Confirmed Workarounds (Crash Eliminated)

1. Force X11 backend (most reliable)
   QT_QPA_PLATFORM=xcb vlc --avcodec-hw=none playlist.xspf

2. Disable hardware decoding
   vlc --avcodec-hw=none playlist.xspf

3. Change video output module (Wayland)
   vlc --vout=opengl --avcodec-hw=none playlist.xspf

With these applied:

No segfaults observed

Playlist playback remains stable

Additional Notes

This issue appears specific to Wayland on Raspberry Pi OS Bookworm

The same workload does not crash under X11

The playlist itself is not malformed; it simply exercises repeated video output teardown/recreate

This behavior is reproducible and produces consistent core dumps

Impact

This affects:

Normal VLC playlist playback

Any application embedding or controlling VLC (libVLC / python-vlc)

Digital signage / scheduled playback use cases on Raspberry Pi 5

Because the failure is a hard SIGSEGV, it can crash entire applications that embed VLC.

Request

Please advise:

Whether this is a known issue with VLC on Wayland for Raspberry Pi OS

Whether dmabuf or QtWayland patches are planned

If additional logging or testing is needed, I’m happy to provide it

Thank you for your work maintaining VLC on Raspberry Pi OS.

[jc-kynesim]

Thank you for the report. With my simple testing I can't reproduce your crash. But we have had issues with Wayland queues on stream change in the past so I find it quite believable.

Can you give me a clue how quickly your crashes occur (I assume it is based on stream changes rather than duration, but if it is duration based that would be odd but interesting)

Could you test on a current Trixie image and see if the issue happens there?

Do all the files in the playlist have the same encoding and resolution? If not does the crash happen only when going from one type to another?

I assume you are using lawbc as your Wayland server, if not then what? Is there any wayland setup that isn't out of the box?

Is the output to a single HDMI monitor - if not then what?

If it is possible to point me at an example playlist and files that provokes the crash, then that would be very helpful. The smaller and simpler the better.

P.S. Sorry about the delay in replying, Christmas & Illness delayed me.