kamoso crashes when switching camera

[Heinrich Schuchardt]

I have two cameras attached to my Ubuntu Mantic system:

045e:0772 Microsoft Corp. LifeCam Studio
05e3:f12a Genesys Logic, Inc. Digital Microscope

In the configuration dialogue I try to switch to camera 05e3:f12a. A crash occurs each time I try.

ProblemType: Bug
DistroRelease: Ubuntu 23.10
Package: kamoso 23.04.2-0ubuntu1
ProcVersionSignature: Ubuntu 6.3.0-7.7-generic 6.3.5
Uname: Linux 6.3.0-7-generic x86_64
NonfreeKernelModules: zfs nvidia_modeset nvidia
ApportVersion: 2.26.1-0ubuntu3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: KDE
Date: Mon Jun 26 15:02:58 2023
InstallationDate: Installed on 2021-05-26 (760 days ago)
InstallationMedia: Kubuntu 21.04 "Hirsute Hippo" - Release amd64 (20210420)
SourcePackage: kamoso
UpgradeStatus: No upgrade log present (probably fresh install)

[Heinrich Schuchardt (xypron)]

This is the call stack according to the crash dump:

#0 __pthread_kill_implementation (no_tid=0, signo=11, threadid=<optimized out>) at ./nptl/pthread_kill.c:44
44 ./nptl/pthread_kill.c: No such file or directory.
[Current thread is 1 (Thread 0x7fcee5be09c0 (LWP 101680))]
(gdb) up
#1 __pthread_kill_internal (signo=11, threadid=<optimized out>) at ./nptl/pthread_kill.c:78
78 in ./nptl/pthread_kill.c
(gdb)
#2 __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=11) at ./nptl/pthread_kill.c:89
89 in ./nptl/pthread_kill.c
(gdb)
#3 0x00007fcee9c3c406 in __GI_raise (sig=11) at ../sysdeps/posix/raise.c:26
26 ../sysdeps/posix/raise.c: No such file or directory.
(gdb)
#4 0x00007fceeb2f5503 in KCrash::defaultCrashHandler(int) () from /lib/x86_64-linux-gnu/libKF5Crash.so.5
(gdb)
#5 <signal handler called>
(gdb)
#6 0x00007fceea3b66d3 in g_list_foreach () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
(gdb)
#7 0x00007fceea3bc53f in g_list_free_full () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
(gdb)
#8 0x00007fceea51c70b in ?? () from /lib/x86_64-linux-gnu/libgstreamer-1.0.so.0
(gdb)
#9 0x00007fceeb3c1da0 in g_object_unref () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
(gdb)
#10 0x00007fceea4f6858 in ?? () from /lib/x86_64-linux-gnu/libgstreamer-1.0.so.0
(gdb)
#11 0x00007fceea4f1c56 in gst_bin_remove () from /lib/x86_64-linux-gnu/libgstreamer-1.0.so.0
(gdb)
#12 0x00007fceea4f23b3 in ?? () from /lib/x86_64-linux-gnu/libgstreamer-1.0.so.0
(gdb)
#13 0x00007fceeb3c1da0 in g_object_unref () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
(gdb)
#14 0x000055f72d19bd73 in ?? ()
(gdb)
#15 0x00007fceea50584f in ?? () from /lib/x86_64-linux-gnu/libgstreamer-1.0.so.0
(gdb)
#16 0x00007fceea3c032f in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
(gdb)
#17 0x00007fceea41b148 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
(gdb)
#18 0x00007fceea3bf170 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
(gdb)
#19 0x00007fceea9150ea in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
(gdb)
#20 0x00007fceea8b99db in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
(gdb)
#21 0x00007fceea8c1e2a in QCoreApplication::exec() () from /lib/x86_64-linux-gnu/libQt5Core.so.5
(gdb)
#22 0x000055f72d196585 in ?? ()
(gdb)
#23 0x00007fcee9c23a90 in __libc_start_call_main (main=main@entry=0x55f72d1947c0, argc=argc@entry=1, argv=argv@entry=0x7ffc4722ee78) at ../sysdeps/nptl/libc_start_call_main.h:58
58 ../sysdeps/nptl/libc_start_call_main.h: No such file or directory.
(gdb)
#24 0x00007fcee9c23b49 in __libc_start_main_impl (main=0x55f72d1947c0, argc=1, argv=0x7ffc4722ee78, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>,
    stack_end=0x7ffc4722ee68) at ../csu/libc-start.c:360
360 ../csu/libc-start.c: No such file or directory.
(gdb)
#25 0x000055f72d1971b5 in ?? ()
(gdb)
Initial frame selected; you cannot go up.

[Heinrich Schuchardt (xypron)]

Here is another call stack with a crash:

Thread 1 "kamoso" received signal SIGSEGV, Segmentation fault.
g_type_check_instance_is_fundamentally_a (type_instance=0x5555563169b0, fundamental_type=0x50 [None]) at ../../../gobject/gtype.c:4167
Downloading source file /usr/src/glib2.0-2.76.3-1ubuntu1/debian/build/deb/../../../gobject/gtype.c
4167 return node && (NODE_FUNDAMENTAL_TYPE(node) == fundamental_type);
(gdb) up
#1 0x00007ffff6eecfac in g_object_notify (object=0x5555563169b0, property_name=0x7fffd80c6901 "zoom") at ../../../gobject/gobject.c:1584
1584 g_return_if_fail (G_IS_OBJECT (object));
(gdb) up
#2 0x00007ffff6edc010 in g_closure_invoke (closure=0x55555645bad0, return_value=0x0, n_param_values=2, param_values=0x7fffffffcb80, invocation_hint=0x7fffffffcb00)
    at ../../../gobject/gclosure.c:832
Downloading source file /usr/src/glib2.0-2.76.3-1ubuntu1/debian/build/deb/../../../gobject/gclosure.c
u832 marshal (closure,
(gdb) up
#3 0x00007ffff6f093d6 in signal_emit_unlocked_R.isra.0 (node=node@entry=0x5555559a0cc0, detail=detail@entry=2335, instance=instance@entry=0x555556250c90,
    emission_return=emission_return@entry=0x0, instance_and_params=instance_and_params@entry=0x7fffffffcb80) at ../../../gobject/gsignal.c:3812
Downloading source file /usr/src/glib2.0-2.76.3-1ubuntu1/debian/build/deb/../../../gobject/gsignal.c
3812 g_closure_invoke (handler->closure,
(gdb) up
#4 0x00007ffff6ef969a in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>, var_args=var_args@entry=0x7fffffffcd40)
    at ../../../gobject/gsignal.c:3565
3565 signal_emit_unlocked_R (node, detail, instance, NULL, instance_and_params);
(gdb) up
#5 0x00007ffff6ef9923 in g_signal_emit (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>) at ../../../gobject/gsignal.c:3622
3622 g_signal_emit_valist (instance, signal_id, detail, var_args);
(gdb) up
#6 0x00007ffff6ee6dc4 in g_object_dispatch_properties_changed (object=0x555556250c90, n_pspecs=<optimized out>, pspecs=<optimized out>) at ../../../gobject/gobject.c:1428
1428 g_signal_emit (object, gobject_signals[NOTIFY], g_param_spec_get_name_quark (pspecs[i]), pspecs[i]);
(gdb)
#7 0x00007ffff58ed458 in gst_object_dispatch_properties_changed (object=0x555556250c90, n_pspecs=1, pspecs=0x7fffffffceb0) at ../gst/gstobject.c:455
455 ((GObjectClass *)
(gdb)
#8 ...

[Heinrich Schuchardt (xypron)]

Thread 1 "kamoso" received signal SIGSEGV, Segmentation fault.
0x00007ffff57b66d3 in g_list_foreach (list=list@entry=0x3f800000 = {...}, func=0x7ffff590d640 <gst_context_unref.lto_priv.1.lto_priv>, user_data=user_data@entry=0x0)
    at ../../../glib/glist.c:1091
1091 GList *next = list->next;
(gdb) up
#1 0x00007ffff57bc53f in g_list_free_full (list=0x3f800000 = {...}, free_func=<optimized out>) at ../../../glib/glist.c:246
246 g_list_foreach (list, (GFunc) free_func, NULL);
(gdb)
#2 0x00007ffff591c70b in gst_element_dispose (object=0x555556317b50) at ../gst/gstelement.c:3434
3434 g_list_free_full (element->contexts, (GDestroyNotify) gst_context_unref);
(gdb)
#3 0x00007ffff6ee9da0 in g_object_unref (_object=0x555556317b50) at ../../../gobject/gobject.c:3891
3891 G_OBJECT_GET_CLASS (object)->dispose (object);
(gdb)
#4 0x00007ffff58ed343 in gst_object_unref (object=<optimized out>) at ../gst/gstobject.c:267
267 g_object_unref (object);
(gdb)
#5 0x00007ffff58f6858 in gst_bin_remove_func (bin=0x555556ca81f0, element=<optimized out>) at ../gst/gstbin.c:1817
1817 gst_object_unref (element);
(gdb)
#6 0x00007ffff58f1c56 in gst_bin_remove (bin=bin@entry=0x555556ca81f0, element=0x555556317b50) at ../gst/gstbin.c:1868
1868 result = bclass->remove_element (bin, element);
(gdb)
#7 0x00007ffff58f23b3 in gst_bin_dispose (object=0x555556ca81f0) at ../gst/gstbin.c:527
527 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
(gdb)
#8 0x00007ffff6ee9da0 in g_object_unref (_object=0x555556ca81f0) at ../../../gobject/gobject.c:3891
3891 G_OBJECT_GET_CLASS (object)->dispose (object);
(gdb)
#9 0x000055555556cd73 in WebcamControl::onBusMessage (message=<optimized out>, this=<optimized out>) at /usr/src/kamoso-23.04.2-0ubuntu1/src/video/webcamcontrol.cpp:306
306 stop();
(gdb)
#10 webcamWatch (message=<optimized out>, user_data=0x7fffffffd730) at /usr/src/kamoso-23.04.2-0ubuntu1/src/video/webcamcontrol.cpp:244
244 wc->onBusMessage(message);
(gdb)
#11 0x00007ffff590584f in gst_bus_source_dispatch (source=0x555556335b00, callback=0x55555556cc20 <webcamWatch(GstBus*, GstMessage*, gpointer)>, user_data=0x7fffffffd730)
    at ../gst/gstbus.c:821
821 keep = handler (bus, message, user_data); ...

[Heinrich Schuchardt (xypron)]

Upstream bug report
https://bugs.kde.org/show_bug.cgi?id=471467