Version:           unknown (using 4.2.4 (KDE 4.2.4), Kubuntu packages)
Compiler:          cc
OS:                Linux (x86_64) release 2.6.28-13-generic

When dealing with KJots went to infinite loop (Bug 196348) I tryed to kill it with the help of Yakuake:
$ps aux | grep KJots

seajey    4186  0.7  2.4 402056 99020 ?        S    12:56   2:52 kjots -session 1014017617e109000124484279400000039800106_1244845710_321440
seajey    5017  1.8  0.4 224204 19920 ?        S    19:03   0:00 /usr/bin/kwin_killer_helper --pid 4186 --hostname localhost --windowname Найти текст - KJots --applicationname kjots --wid 54528751 --timestamp 22137586
seajey    5045  0.0  0.0   7548   928 pts/1    S+   19:03   0:00 grep kjots

$ sudo kill -9 4186 5017

And then Kwin crashed

$ kwin -v
Qt: 4.5.1
KDE: 4.2.4 (KDE 4.2.4)
KWin: 4.2.4 (KDE 4.2.4)


Приложение: KWin (kwin), сигнал SIGSEGV
0x00007fd81c5a6d21 in nanosleep () from /lib/libc.so.6
Current language:  auto; currently c
[Current thread is 0 (LWP 3987)]

Thread 2 (Thread 0x7fd816be5950 (LWP 3988)):
#0  0x00007fd81c5dd742 in select () from /lib/libc.so.6
#1  0x00007fd81f13c766 in QProcessManager::run (this=0xe00030) at io/qprocess_unix.cpp:305
#2  0x00007fd81f074d02 in QThreadPrivate::start (arg=0xe00030) at thread/qthread_unix.cpp:189
#3  0x00007fd81a7603ba in start_thread (arg=<value optimized out>) at pthread_create.c:297
#4  0x00007fd81c5e4fcd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fd821a99760 (LWP 3987)):
[KCrash Handler]
#5  QProcess::setProcessState (this=0x12340a0, state=QProcess::NotRunning) at io/qprocess.cpp:1329
#6  0x00007fd81f0fe7ef in QProcessPrivate::cleanup (this=0x13224a0) at io/qprocess.cpp:455
#7  0x00007fd81f10421b in QProcessPrivate::_q_processDied (this=0x13224a0) at io/qprocess.cpp:708
#8  0x00007fd81f104301 in QProcess::qt_metacall (this=0x1234260, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff29acc6b0) at .moc/release-shared/moc_qprocess.cpp:109
#9  0x00007fd81f1738d2 in QMetaObject::activate (sender=0x1324600, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x1) at kernel/qobject.cpp:3120
#10 0x00007fd81f1aab0e in QSocketNotifier::activated (this=0x12340a0, _t1=13) at .moc/release-shared/moc_qsocketnotifier.cpp:83
#11 0x00007fd81f178533 in QSocketNotifier::event (this=0x1324600, e=0x7fff29accc80) at kernel/qsocketnotifier.cpp:316
#12 0x00007fd81f867b9d in QApplicationPrivate::notify_helper (this=0xdfb6d0, receiver=0x1324600, e=0x7fff29accc80) at kernel/qapplication.cpp:4057
#13 0x00007fd81f86fdea in QApplication::notify (this=0x7fff29accfa0, receiver=0x1324600, e=0x7fff29accc80) at kernel/qapplication.cpp:4022
#14 0x00007fd820dba84b in KApplication::notify (this=0x7fff29accfa0, receiver=0x1324600, event=0x7fff29accc80) at /build/buildd/kde4libs-4.2.4/kdeui/kernel/kapplication.cpp:307
#15 0x00007fd81f15ddfc in QCoreApplication::notifyInternal (this=0x7fff29accfa0, receiver=0x1324600, event=0x7fff29accc80) at kernel/qcoreapplication.cpp:610
#16 0x00007fd81f1877a9 in socketNotifierSourceDispatch (source=0xdff270) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#17 0x00007fd81a9af20a in IA__g_main_context_dispatch (context=0xdfe120) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:1814
#18 0x00007fd81a9b28e0 in g_main_context_iterate (context=0xdfe120, block=1, dispatch=1, self=<value optimized out>) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:2448
#19 0x00007fd81a9b2a7c in IA__g_main_context_iteration (context=0xdfe120, may_block=1) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:2511
#20 0x00007fd81f18752f in QEventDispatcherGlib::processEvents (this=0xde7a50, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:324
#21 0x00007fd81f90070f in QGuiEventDispatcherGlib::processEvents (this=0x12340a0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#22 0x00007fd81f15c6a2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 699190944}) at kernel/qeventloop.cpp:149
#23 0x00007fd81f15ca6d in QEventLoop::exec (this=0x7fff29accee0, flags={i = 699191024}) at kernel/qeventloop.cpp:200
#24 0x00007fd81f15ed34 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#25 0x00007fd82162a9ef in kdemain (argc=3, argv=0x7fff29acd478) at /build/buildd/kdebase-workspace-4.2.4/kwin/main.cpp:519
#26 0x00007fd81c51d5a6 in __libc_start_main (main=0x4008b0 <main>, argc=3, ubp_av=0x7fff29acd478, init=0x4008e0 <__libc_csu_init>, fini=<value optimized out>, rtld_fini=<value optimized out>, 
    stack_end=0x7fff29acd468) at libc-start.c:220
#27 0x00000000004007e9 in _start () at ../sysdeps/x86_64/elf/start.S:113