Since an update to the packages on Debian testing last night, the KDE desktop crashes on boot, giving a message that prompts to create a backtrace. Here is that backtrace.
As you can see, running Debian Jessie, versions of KDE packages are 4.10.5-1 or 4.10.5-2. kernel 3.10-3-amd64. I have a wallpaper slideshow which appears to be one of the things crashing.
What is the source of this problem? This is the first time my desktop has failed in 3 years of KDE atop debian. Will be happy for a solution as have had to fall back to another desktop.



Reproducible: Always

Steps to Reproduce:
1. Boot with user configuration into KDE desktop. (guest account with default configuration boots normally.)
2. Error message appears indicating that the plasma desktop has crashed. Ctrl-Alt-Del will still bring up a restart/shutdown/logout menu with the correct appearance settings.
3.
Actual Results:  
KDE desktop does not appear at boot.

Expected Results:  
KDE desktop renders computer available for use when started up.

Application: plasma-desktop (4.10.5)
KDE Platform Version: 4.10.5
Qt Version: 4.8.6
Operating System: Linux 3.10-3-amd64 x86_64
Distribution: Debian GNU/Linux testing (jessie)

-- Information about the crash:
<In detail, tell us what you were doing  when the application crashed.>

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fd0f8287780 (LWP 7946))]

Thread 3 (Thread 0x7fd0d9719700 (LWP 7957)):
#0  0x00007fd0ebff8e35 in __GI___pthread_mutex_lock (mutex=0x239eb10) at pthread_mutex_lock.c:95
#1  0x00007fd0eb724291 in g_mutex_lock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fd0eb6e4a2b in g_main_context_query () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fd0eb6e5102 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fd0eb6e55fa in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007fd0e05abd26 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#6  0x00007fd0eb7091d5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#7  0x00007fd0ebff6e0e in start_thread (arg=0x7fd0d9719700) at pthread_create.c:311
#8  0x00007fd0f7b889ed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 2 (Thread 0x7fd0ce491700 (LWP 7959)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fd0f174ba4b in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#2  0x00007fd0f174ba89 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#3  0x00007fd0ebff6e0e in start_thread (arg=0x7fd0ce491700) at pthread_create.c:311
#4  0x00007fd0f7b889ed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 1 (Thread 0x7fd0f8287780 (LWP 7946)):
[KCrash Handler]
#6  0x00007fd0f46d7b80 in QMetaObject::cast (this=this@entry=0x7fd0f7a8e560 <Plasma::AppletScript::staticMetaObject>, obj=obj@entry=0x2a73bb0) at kernel/qmetaobject.cpp:275
#7  0x00007fd0f77371cf in qobject_cast<Plasma::WallpaperScript*> (object=0x2a73bb0) at /usr/include/qt4/QtCore/qobject.h:380
#8  create<Plasma::WallpaperScript> (args=..., keyword=..., parent=<optimized out>, parentWidget=<optimized out>, this=<optimized out>) at ../../kdecore/util/kpluginfactory.h:533
#9  createInstance<Plasma::WallpaperScript> (error=<optimized out>, args=..., parent=<optimized out>, parentWidget=<optimized out>, this=<optimized out>) at ../../kdecore/services/kservice.h:559
#10 createInstance<Plasma::WallpaperScript> (error=<optimized out>, args=..., parent=<optimized out>, this=<optimized out>) at ../../kdecore/services/kservice.h:536
#11 Plasma::loadEngine (language=..., type=type@entry=Plasma::AppletComponent, parent=parent@entry=0x2a74140) at ../../plasma/scripting/scriptengine.cpp:185
#12 0x00007fd0f7737796 in Plasma::loadScriptEngine (language=..., applet=0x2a74140) at ../../plasma/scripting/scriptengine.cpp:209
#13 0x00007fd0f768b9ad in Plasma::AppletPrivate::init (this=0x290aa70, packagePath=...) at ../../plasma/applet.cpp:2799
#14 0x00007fd0f7690a53 in Plasma::Applet::Applet (this=0x2a74140, parentObject=0x0, args=...) at ../../plasma/applet.cpp:193
#15 0x00007fd0f76cdf62 in Plasma::PluginLoader::loadApplet (this=<optimized out>, name=..., appletId=<optimized out>, appletId@entry=172, args=...) at ../../plasma/pluginloader.cpp:134
#16 0x00007fd0f76832a5 in Plasma::Applet::load (appletName=..., appletId=appletId@entry=172, args=...) at ../../plasma/applet.cpp:2451
#17 0x00007fd0f76a04e4 in Plasma::ContainmentPrivate::addApplet (this=0x291caf0, name=..., args=..., appletGeometry=..., id=id@entry=172, delayInit=delayInit@entry=true) at ../../plasma/containment.cpp:2221
#18 0x00007fd0f76a4be5 in Plasma::Containment::restoreContents (this=0x28f0990, group=...) at ../../plasma/containment.cpp:497
#19 0x00007fd0f76a1734 in Plasma::Containment::restore (this=0x28f0990, group=...) at ../../plasma/containment.cpp:337
#20 0x00007fd0f76b0fd1 in Plasma::CoronaPrivate::importLayout (this=0x250b2e0, conf=..., mergeConfig=mergeConfig@entry=false) at ../../plasma/corona.cpp:1061
#21 0x00007fd0f76b1adc in Plasma::Corona::loadLayout (this=this@entry=0x226f210, configName=...) at ../../plasma/corona.cpp:278
#22 0x00007fd0f76b1b92 in Plasma::Corona::initializeLayout (this=0x226f210, configName=...) at ../../plasma/corona.cpp:181
#23 0x00007fd0f7e9d27a in ?? () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#24 0x00007fd0f7e9d885 in ?? () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#25 0x00007fd0f7ea1b35 in ?? () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#26 0x00007fd0f46e987e in QObject::event (this=this@entry=0x22af9a0, e=e@entry=0x25f1050) at kernel/qobject.cpp:1194
#27 0x00007fd0f46d5a5c in QCoreApplication::event (this=this@entry=0x22af9a0, e=e@entry=0x25f1050) at kernel/qcoreapplication.cpp:1761
#28 0x00007fd0f3a76803 in QApplication::event (this=0x22af9a0, e=0x25f1050) at kernel/qapplication.cpp:2549
#29 0x00007fd0f3a7175c in QApplicationPrivate::notify_helper (this=this@entry=0x22c8b00, receiver=receiver@entry=0x22af9a0, e=e@entry=0x25f1050) at kernel/qapplication.cpp:4567
#30 0x00007fd0f3a77dd0 in QApplication::notify (this=this@entry=0x22af9a0, receiver=receiver@entry=0x22af9a0, e=e@entry=0x25f1050) at kernel/qapplication.cpp:4353
#31 0x00007fd0f53cacfa in KApplication::notify (this=0x22af9a0, receiver=0x22af9a0, event=0x25f1050) at ../../kdeui/kernel/kapplication.cpp:311
#32 0x00007fd0f46d133d in QCoreApplication::notifyInternal (this=0x22af9a0, receiver=receiver@entry=0x22af9a0, event=event@entry=0x25f1050) at kernel/qcoreapplication.cpp:949
#33 0x00007fd0f46d489f in sendEvent (event=0x25f1050, receiver=0x22af9a0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#34 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x22361f0) at kernel/qcoreapplication.cpp:1573
#35 0x00007fd0f46d4d43 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1466
#36 0x00007fd0f46febf3 in sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236
#37 postEventSourceDispatch (s=0x22c8f80) at kernel/qeventdispatcher_glib.cpp:280
#38 0x00007fd0eb6e4ea6 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#39 0x00007fd0eb6e51f8 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#40 0x00007fd0eb6e529c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#41 0x00007fd0f46fe4b5 in QEventDispatcherGlib::processEvents (this=0x2237ad0, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#42 0x00007fd0f3b0f896 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#43 0x00007fd0f46cff9f in QEventLoop::processEvents (this=this@entry=0x7fff1aff3f30, flags=...) at kernel/qeventloop.cpp:149
#44 0x00007fd0f46d0295 in QEventLoop::exec (this=this@entry=0x7fff1aff3f30, flags=...) at kernel/qeventloop.cpp:204
#45 0x00007fd0f46d58db in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1221
#46 0x00007fd0f7e882ec in kdemain () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#47 0x00007fd0f7ac1995 in __libc_start_main (main=0x4006e0, argc=1, ubp_av=0x7fff1aff4188, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff1aff4178) at libc-start.c:260
#48 0x000000000040070e in _start ()