Bug 506914

Summary:	Kdenlive segfaults using all 25.04.x binaries on pop-os
Product:	[Applications] kdenlive	Reporter:	mark_vejvoda
Component:	User Interface & Miscellaneous	Assignee:	Jean-Baptiste Mardelle <jb>
Status:	REPORTED ---
Severity:	crash	CC:	balooii, fritzibaby
Priority:	NOR	Keywords:	triaged
Version First Reported In:	25.04.3
Target Milestone:	---
Platform:	Pop!_OS
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description mark_vejvoda 2025-07-11 14:45:05 UTC

Crash happens on all 25.04.x releases and never had a crash in previous years/releases using the same hardware

lsb_release --all
No LSB modules are available.
Distributor ID:	Pop
Description:	Pop!_OS 22.04 LTS
Release:	22.04
Codename:	jammy

Always get segfault at the same point from all kdenlive 25.x binaries, including daily builds:

gdb ./kdenlive-25.04.3-x86_64.AppImage
GNU gdb (Ubuntu 12.1-0ubuntu1~22.04.2) 12.1
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Reading symbols from ./kdenlive-25.04.3-x86_64.AppImage...
(No debugging symbols found in ./kdenlive-25.04.3-x86_64.AppImage)
(gdb) run
Starting program: /home/softcoder/kdenlive-standalone/kdenlive-25.04.3-x86_64.AppImage 
[Detaching after fork from child process 1092820]
process 1092817 is executing new program: /usr/bin/env
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
process 1092817 is executing new program: /usr/bin/bash
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Detaching after fork from child process 1092826]
[Detaching after fork from child process 1092828]
process 1092817 is executing new program: /tmp/.mount_kdenlikgeNpL/usr/bin/kdenlive
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffe6dff640 (LWP 1092830)]
[New Thread 0x7fffe65fe640 (LWP 1092831)]
kf.notifications: Failed to play sound with canberra: No such driver
[New Thread 0x7fffe53ff640 (LWP 1092847)]
[New Thread 0x7fffe4bfe640 (LWP 1092848)]
profilePath from $MLT_PROFILES_PATH:  "/tmp/.mount_kdenlikgeNpL/usr/share/mlt-7/profiles/"
meltPath from KdenliveSetting::meltPath:  "/tmp/.mount_kdenlikgeNpL/usr/bin/melt"
[New Thread 0x7fffcffff640 (LWP 1092852)]
[New Thread 0x7fffcf014640 (LWP 1092853)]
[New Thread 0x7fffce813640 (LWP 1092854)]
Starting render server
ZZZZZZZZZZZZZZZZZZZZZZZ

STARTING TASKMANAGER CLOSURE, ACTIVE THREADS:  0 
EXCEPTIONS:  QList() 

ZZZZZZZZZZZZZZZZZZZZZZZ
plugin not available: "region"
plugin not available: "region"
Empty metadata for  "glsl.manager"
kf.i18n: Trying to convert empty KLocalizedString to QString.
Empty metadata for  "telecide"
plugin not available: "avfilter.acompressor"
plugin not available: "avfilter.aecho"
plugin not available: "avfilter.agate"
plugin not available: "avfilter.atadenoise"
plugin not available: "avfilter.bs2b"
plugin not available: "avfilter.bwdif"
plugin not available: "avfilter.deblock"
plugin not available: "avfilter.dedot"
plugin not available: "avfilter.deflate"
plugin not available: "avfilter.derain"
plugin not available: "avfilter.doubleweave"
plugin not available: "avfilter.field"
plugin not available: "avfilter.framestep"
plugin not available: "avfilter.fspp"
plugin not available: "avfilter.graphmonitor"
Failed to parse file "/usr/share/kdenlive/effects/avfilter_highshelf.xml" to QDomDocument
plugin not available: "avfilter.hqdn3d"
plugin not available: "avfilter.inflate"
plugin not available: "avfilter.lagfun"
plugin not available: "avfilter.loudnorm"
Failed to parse file "/usr/share/kdenlive/effects/avfilter_lowpass.xml" to QDomDocument
Failed to parse file "/usr/share/kdenlive/effects/avfilter_lowshelf.xml" to QDomDocument
plugin not available: "avfilter.random"
plugin not available: "avfilter.removegrain"
plugin not available: "avfilter.separatefields"
plugin not available: "avfilter.shuffleplanes"
plugin not available: "avfilter.sofalizer"
plugin not available: "avfilter.sr"
plugin not available: "avfilter.tmix"
plugin not available: "avfilter.w3fdif"
plugin not available: "avfilter.weave"
plugin not available: "avfilter.yadif"
plugin not available: "frei0r.baltan"
plugin not available: "frei0r.bgsubtract0r"
plugin not available: "frei0r.delay0r"
plugin not available: "frei0r.delaygrab"
plugin not available: "frei0r.lightgraffiti"
plugin not available: "frei0r.lightgraffiti"
Failed to parse file "/usr/share/kdenlive/effects/frei0r_softglow.xml" to QDomDocument
plugin not available: "frei0r.tehRoxx0r"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "movit.unsharp_mask"
plugin not available: "region"
plugin not available: "timewarp"
Failed to parse file "/usr/share/kdenlive/effects/tracker.xml" to QDomDocument
plugin not available: "avfilter.acompressor"
plugin not available: "avfilter.aecho"
plugin not available: "avfilter.agate"
plugin not available: "avfilter.atadenoise"
plugin not available: "avfilter.bs2b"
plugin not available: "avfilter.bwdif"
plugin not available: "avfilter.deblock"
plugin not available: "avfilter.dedot"
plugin not available: "avfilter.deflate"
plugin not available: "avfilter.derain"
plugin not available: "avfilter.doubleweave"
plugin not available: "avfilter.field"
plugin not available: "avfilter.framestep"
plugin not available: "avfilter.fspp"
plugin not available: "avfilter.graphmonitor"
plugin not available: "avfilter.hqdn3d"
plugin not available: "avfilter.inflate"
plugin not available: "avfilter.lagfun"
plugin not available: "avfilter.loudnorm"
plugin not available: "avfilter.random"
plugin not available: "avfilter.removegrain"
plugin not available: "avfilter.separatefields"
plugin not available: "avfilter.shuffleplanes"
plugin not available: "avfilter.sofalizer"
plugin not available: "avfilter.sr"
plugin not available: "avfilter.tmix"
plugin not available: "avfilter.w3fdif"
plugin not available: "avfilter.weave"
plugin not available: "avfilter.yadif"
plugin not available: "frei0r.baltan"
plugin not available: "frei0r.bgsubtract0r"
plugin not available: "frei0r.delay0r"
plugin not available: "frei0r.delaygrab"
plugin not available: "frei0r.lightgraffiti"
plugin not available: "frei0r.lightgraffiti"
plugin not available: "frei0r.tehRoxx0r"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "movit.unsharp_mask"
plugin not available: "timewarp"
[New Thread 0x7fffce012640 (LWP 1092856)]
qt.multimedia.ffmpeg: Using Qt multimedia with FFmpeg version 7.1 nonfree and unredistributable
[New Thread 0x7fffcc9ff640 (LWP 1092857)]
[New Thread 0x7fffb8fff640 (LWP 1092861)]
[New Thread 0x7fffa8dde640 (LWP 1092862)]
[Thread 0x7fffb8fff640 (LWP 1092861) exited]
[Thread 0x7fffa8dde640 (LWP 1092862) exited]

Thread 1 "AppRun.wrapped" received signal SIGSEGV, Segmentation fault.
0x00007ffff36e9d74 in XDisplayString () from /lib/x86_64-linux-gnu/libX11.so.6
(gdb) bt
#0  0x00007ffff36e9d74 in XDisplayString () from /lib/x86_64-linux-gnu/libX11.so.6
#1  0x00007fffb8405f05 in __vaDriverInit_1_0 () from /usr/lib/x86_64-linux-gnu/dri/nvidia_drv_video.so
#2  0x00007fffee97ab6f in vaInitialize () from /tmp/.mount_kdenlikgeNpL/usr/bin/../lib/libva.so.2
#3  0x00007ffff0c40fcc in ?? () from /tmp/.mount_kdenlikgeNpL/usr/bin/../lib/libavutil.so.59
#4  0x00007ffff0c3867c in av_hwdevice_ctx_create () from /tmp/.mount_kdenlikgeNpL/usr/bin/../lib/libavutil.so.59
#5  0x00007fffd41266f9 in ?? () from /tmp/.mount_kdenlikgeNpL/usr/plugins/multimedia/libffmpegmediaplugin.so
#6  0x00007fffd4128540 in ?? () from /tmp/.mount_kdenlikgeNpL/usr/plugins/multimedia/libffmpegmediaplugin.so
#7  0x00007fffd4128e41 in ?? () from /tmp/.mount_kdenlikgeNpL/usr/plugins/multimedia/libffmpegmediaplugin.so
#8  0x00007fffd40f8857 in ?? () from /tmp/.mount_kdenlikgeNpL/usr/plugins/multimedia/libffmpegmediaplugin.so
#9  0x00007fffd40f77c4 in ?? () from /tmp/.mount_kdenlikgeNpL/usr/plugins/multimedia/libffmpegmediaplugin.so
#10 0x00007ffff5f884b9 in ?? () from /tmp/.mount_kdenlikgeNpL/usr/bin/../lib/libQt6Multimedia.so.6
#11 0x00007ffff5f8896c in ?? () from /tmp/.mount_kdenlikgeNpL/usr/bin/../lib/libQt6Multimedia.so.6
#12 0x00007ffff5f88a2d in QPlatformMediaIntegration::instance() () from /tmp/.mount_kdenlikgeNpL/usr/bin/../lib/libQt6Multimedia.so.6
#13 0x00007ffff5f94561 in QMediaDevices::audioInputs() () from /tmp/.mount_kdenlikgeNpL/usr/bin/../lib/libQt6Multimedia.so.6
#14 0x0000000000729ba7 in ?? ()
#15 0x0000000000be8110 in ?? ()
#16 0x00000000009355b9 in ?? ()
#17 0x0000000000929f20 in ?? ()
#18 0x0000000000c3dea3 in ?? ()
#19 0x0000000000bedbfa in ?? ()
#20 0x00000000004ea7fc in ?? ()
#21 0x00007ffff0429d90 in __libc_start_call_main (main=main@entry=0x4e75c0, argc=argc@entry=1, argv=argv@entry=0x7fffffffd6d8)
    at ../sysdeps/nptl/libc_start_call_main.h:58
#22 0x00007ffff0429e40 in __libc_start_main_impl (main=0x4e75c0, argc=1, argv=0x7fffffffd6d8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, 
    stack_end=0x7fffffffd6c8) at ../csu/libc-start.c:392
--Type <RET> for more, q to quit, c to continue without paging--Quit

Comment 1 mark_vejvoda 2025-07-11 15:35:42 UTC

I should mention that I am successfully running 24.x binaries on the same OS and hardware

Comment 2 balooii 2025-07-12 10:08:33 UTC

The only thing I could find on the Qt bugtracker was this thing: https://bugreports.qt.io/browse/QTBUG-119254

You can also try installing Kdenlive via Flathub/flatpak. Flatpak release is built against Qt 6.8.x while the AppImage was built with Qt 6.9.x. Maybe that makes a difference? (I assume the ffmpeg/libav version might also be different between those releases but haven't checked).
You mentioned that 24.x releases work for you, I checked the  AppImage for release 24.12.3 and it reports Qt 6.8.x

Comment 3 mark_vejvoda 2025-07-12 20:27:41 UTC

Indeed the flatpak works fine for the latest v25.x

Comment 4 balooii 2025-07-13 08:17:33 UTC

Okay, good to know. What about the other potential issue/fix mentioned in the first link?

Do you have this vdpau driver installed, did it help to uninstall it? No idea how that package(s) is called in PopOS but probably something including "vdpau".

And to follow up on the 2nd point regarding Qt/ffmpeg/avutils version: I did not find anything interesting in the release notes for Qt 6.9 that suggests that there was a breaking change related to QtMultimedia. As we see libav in the strack trace we could choose the gstreamer backend instead of ffmpeg. Easiest would be via environment variable `QT_MEDIA_BACKEND=gstreamer kdenlive`. Problem is that the AppImage does not include gstreamer AFAIK but the flatpak does `flatpak run --env=QT_MEDIA_BACKEND=gstreamer org.kde.kdenlive` (or use Flatseal). Not quite sure but I think that QtMultimedia is only used for recording audio in Kdenlive as audio output goes via MLT. So if you're not using the record functionality this might be a workaround if you want to use the AppImage still.

Comment 5 balooii 2025-07-13 08:29:24 UTC

Found this discussion https://forum.manjaro.org/t/digikam-is-now-throwing-a-segfault-on-startup/174490/1 which is pretty much the same as we've been discussing here.

So please check the libva/vdpau/nvidia situation first, seems to be the root cause...

Comment 6 mark_vejvoda 2025-07-14 22:35:56 UTC

I have all options installed for pop-os related to libva-*

sudo apt install libva-
libva-dev       libva-drm2      libva-glx2      libva-wayland2  libva-x11-2

All are on the latest version for pop-os

So there is no option for libva-nvidia-driver that i have avaialble in my pop-os