Version:            (using KDE 4.2.0)
OS:                Linux
Installed from:    Debian testing/unstable Packages

When I restarted the HAL daemon (hald), after a few seconds it seemed like plasma restarted itself (the desktop disappeared, then reappeared and started rebuilding the systray icons one by one, much like what happens at login). Before finishing, the whole KDE session terminated and threw me back to the kdm login prompt. This is with KDE 4.2.0.

In an earlier attempt with KDE 4.2.0 RC1 (from unofficial kde42.debian.net packages), restarting hald just caused kded to crash with the following stack trace:

Program: KDE-demon (kded4), signal SIGABRT
0x00007f6f3da5cff1 in nanosleep () from /lib/libc.so.6

Thread 1 (Thread 0x7f6f3e0056f0 (LWP 31891)):
[KCrash Handler]
#5  0x00007f6f3d9f0ed5 in raise () from /lib/libc.so.6
#6  0x00007f6f3d9f23f3 in abort () from /lib/libc.so.6
#7  0x00007f6f3d5e75a5 in qt_message_output (msgType=QtFatalMsg, buf=<value optimized out>) at global/qglobal.cpp:2102
#8  0x00007f6f3d5e76e7 in qFatal (msg=<value optimized out>) at global/qglobal.cpp:2303
#9  0x00007f6f387cf30b in Solid::DeviceManagerPrivate::_k_deviceAdded (this=0x7701e0, udi=@0xda26b0) at ../../../solid/solid/devicemanager.cpp:164
#10 0x00007f6f387cf3e7 in Solid::DeviceManagerPrivate::qt_metacall (this=0x7701e0, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7fff4613c940) at ./devicemanager_p.moc:72
#11 0x00007f6f3d6eb6e4 in QMetaObject::activate (sender=0x7991f0, from_signal_index=<value optimized out>, to_signal_index=4, argv=0xffffffffffffffff) at kernel/qobject.cpp:3031
#12 0x00007f6f387deb02 in Solid::Ifaces::DeviceManager::deviceAdded (this=0x7c93, _t1=<value optimized out>) at ./ifaces/devicemanager.moc:79
#13 0x00007f6f3880244c in Solid::Backends::Hal::HalManager::qt_metacall (this=0x7991f0, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7fff4613ca40) at ./backends/hal/halmanager.moc:70
#14 0x00007f6f3c0b2db3 in QDBusConnectionPrivate::deliverCall (this=0x741cf0, object=0x7991f0, msg=@0xd998d8, metaTypes=@0xd998e0, slotIdx=6) at qdbusintegrator.cpp:849
#15 0x00007f6f3c0b9dff in QDBusCallDeliveryEvent::placeMetaCall (this=0x0, object=0x7c93) at qdbusintegrator_p.h:130
#16 0x00007f6f3d6e6355 in QObject::event (this=0x7991f0, e=0xd99890) at kernel/qobject.cpp:1155
#17 0x00007f6f3b706a5d in QApplicationPrivate::notify_helper (this=0x624460, receiver=0x7991f0, e=0xd99890) at kernel/qapplication.cpp:3803
#18 0x00007f6f3b70e7da in QApplication::notify (this=0x7fff4613d670, receiver=0x7991f0, e=0xd99890) at kernel/qapplication.cpp:3768
#19 0x00007f6f3cd05d8b in KApplication::notify (this=0x7fff4613d670, receiver=0x7991f0, event=0xd99890) at ../../kdeui/kernel/kapplication.cpp:307
#20 0x00007f6f3d6d7391 in QCoreApplication::notifyInternal (this=0x7fff4613d670, receiver=0x7991f0, event=0xd99890) at kernel/qcoreapplication.cpp:587
#21 0x00007f6f3d6d802a in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x602e40) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:209
#22 0x00007f6f3d6ffa93 in postEventSourceDispatch (s=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:214
#23 0x00007f6f3a982aab in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#24 0x00007f6f3a98626d in ?? () from /usr/lib/libglib-2.0.so.0
#25 0x00007f6f3a98642b in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#26 0x00007f6f3d6ff71f in QEventDispatcherGlib::processEvents (this=0x6243d0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:319
#27 0x00007f6f3b79847f in QGuiEventDispatcherGlib::processEvents (this=0x7c93, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:198
#28 0x00007f6f3d6d5cb2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 1175704944}) at kernel/qeventloop.cpp:143
#29 0x00007f6f3d6d5e3d in QEventLoop::exec (this=0x7fff4613d5b0, flags={i = 1175705024}) at kernel/qeventloop.cpp:194
#30 0x00007f6f3d6d82ed in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#31 0x00007f6f3dd1e379 in kdemain (argc=1, argv=0x7fff4613da28) at ../../kded/kded.cpp:938
#32 0x00007f6f3d9dd1a6 in __libc_start_main () from /lib/libc.so.6
#33 0x0000000000400629 in _start ()