Application: muon (2.1.3)
KDE Platform Version: 4.11.5
Qt Version: 4.8.4
Operating System: Linux 3.11.0-19-generic i686
Distribution: Ubuntu 13.10

-- Information about the crash:
- What I was doing when the application crashed:
Steps to reproduce:  This may be a little hard to follow, so I might append a video so you don't get lost, but it's entirely reproducible - I've done it over a dozen times straight.
1) Open Muon Package Manager.
2) Type "wallpapers" into the search.
3) (optional step - just so you follow along) Sort by Status: Installed.  You should have two:
  kde-wallpapers
  kde-wallpapers-default
4) Right-click on kde-wallpapers and mark it for removal (or purge).
5) When the "Confirm Additional Changes" notice comes up, click cancel.
6) Right-click on kde-wallpapers-default and mark it for removal (or purge).  The message will come up Unable to Mark Package "The kde-wallpapers-default package could not be marked for installation or upgrade:"  (Note the colon at the end of the message, but there's nothing that follows.  The cursor stays spinning like it's thinking about something, but it really isn't.)
7) Click OK, or x-out that message.
8) Right-click on any package and click "Lock at Current Version".
9) When the authentication screen appears, you can do either of these:
 a) Wait about 25-30 seconds and the crash will happen, or
 b) Press "Cancel" and you will get the message:
  "The package **[package name]** could not be locked. Failed to write lock file."
  When you press OK on that message, the crash will happen.


- Unusual behavior I noticed:

If you do step 6 before step 4, you don't get the "Unable to Mark Package" message.

The crash can be reproduced every time.

-- Backtrace:
Application: Muon Package Manager (muon), signal: Segmentation fault
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0xb4700980 (LWP 2524))]

Thread 3 (Thread 0xb121fb40 (LWP 2529)):
#0  0xb770a424 in __kernel_vsyscall ()
#1  0xb5d894d2 in clock_gettime (clock_id=1, tp=0xb121efc8) at ../sysdeps/unix/clock_gettime.c:115
#2  0xb5fe23ec in do_gettime (frac=0xb121efc0, sec=0xb121efb8) at tools/qelapsedtimer_unix.cpp:123
#3  qt_gettime () at tools/qelapsedtimer_unix.cpp:140
#4  0xb60c7fd2 in updateCurrentTime (this=0xb0902074) at kernel/qeventdispatcher_unix.cpp:354
#5  QTimerInfoList::timerWait (this=0xb0902074, tm=...) at kernel/qeventdispatcher_unix.cpp:461
#6  0xb60c667b in timerSourcePrepareHelper (src=<optimized out>, timeout=0xb121f0bc) at kernel/qeventdispatcher_glib.cpp:136
#7  0xb60c670d in timerSourcePrepare (source=0xb0902040, timeout=0xb121f0bc) at kernel/qeventdispatcher_glib.cpp:169
#8  0xb5030143 in g_main_context_prepare () from /lib/i386-linux-gnu/libglib-2.0.so.0
#9  0xb5030a5f in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#10 0xb5030ca8 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#11 0xb60c68df in QEventDispatcherGlib::processEvents (this=0xb0900468, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#12 0xb60959f3 in QEventLoop::processEvents (this=this@entry=0xb121f228, flags=...) at kernel/qeventloop.cpp:149
#13 0xb6095d19 in QEventLoop::exec (this=this@entry=0xb121f228, flags=...) at kernel/qeventloop.cpp:204
#14 0xb5f84e3d in QThread::exec (this=this@entry=0x89ae2d0) at thread/qthread.cpp:542
#15 0xb6075e14 in QInotifyFileSystemWatcherEngine::run (this=0x89ae2d0) at io/qfilesystemwatcher_inotify.cpp:265
#16 0xb5f8772f in QThreadPrivate::start (arg=0x89ae2d0) at thread/qthread_unix.cpp:338
#17 0xb510ed78 in start_thread (arg=0xb121fb40) at pthread_create.c:311
#18 0xb5d7601e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 2 (Thread 0xaefe4b40 (LWP 2591)):
[KCrash Handler]
#7  0xb73bae2e in Name (this=0x89165b0, this=0x89165b0) at /usr/include/apt-pkg/cacheiterators.h:157
#8  QApt::Package::name (this=this@entry=0x89a9988) at /build/buildd/qapt-2.0.65/src/package.cpp:226
#9  0x0806dada in packageNameLessThan (p1=0x8e5a130, p2=0x89a9988) at /build/buildd/muon-2.1.3/muon/PackageModel/PackageWidget.cpp:65
#10 0x08071891 in QAlgorithmsPrivate::qSortHelper<QList<QApt::Package*>::iterator, QApt::Package*, bool (*)(QApt::Package*, QApt::Package*)> (start=..., end=..., t=@0xae60227c: 0x89a9988, lessThan=lessThan@entry=0x806dac0 <packageNameLessThan(QApt::Package*, QApt::Package*)>) at /usr/include/qt4/QtCore/qalgorithms.h:351
#11 0x0806f21a in qSort<QList<QApt::Package*>::iterator, bool (*)(QApt::Package*, QApt::Package*)> (lessThan=0x806dac0 <packageNameLessThan(QApt::Package*, QApt::Package*)>, end=..., start=...) at /usr/include/qt4/QtCore/qalgorithms.h:187
#12 sortPackages (list=...) at /build/buildd/muon-2.1.3/muon/PackageModel/PackageWidget.cpp:70
#13 0x08071a68 in QtConcurrent::StoredFunctorCall1<QList<QApt::Package*>, QList<QApt::Package*> (*)(QList<QApt::Package*>), QList<QApt::Package*> >::runFunctor (this=0x89c1b18) at /usr/include/qt4/QtCore/qtconcurrentstoredfunctioncall.h:267
#14 0x08072063 in QtConcurrent::RunFunctionTask<QList<QApt::Package*> >::run (this=0x89c1b18) at /usr/include/qt4/QtCore/qtconcurrentrunbase.h:106
#15 0xb5f7a63a in QThreadPoolThread::run (this=0x8e5afb8) at concurrent/qthreadpool.cpp:107
#16 0xb5f8772f in QThreadPrivate::start (arg=0x8e5afb8) at thread/qthread_unix.cpp:338
#17 0xb510ed78 in start_thread (arg=0xaefe4b40) at pthread_create.c:311
#18 0xb5d7601e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131

Thread 1 (Thread 0xb4700980 (LWP 2524)):
#0  0xb770a424 in __kernel_vsyscall ()
#1  0xb511284b in pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_wait.S:187
#2  0xb5d839bc in __pthread_cond_wait (cond=0x8e5af78, mutex=0x8e5af60) at forward.c:149
#3  0xb5f87ca5 in wait (time=4294967295, this=0x8e5af60) at thread/qwaitcondition_unix.cpp:86
#4  QWaitCondition::wait (this=this@entry=0x8e5aec0, mutex=mutex@entry=0x8e5aeac, time=time@entry=4294967295) at thread/qwaitcondition_unix.cpp:158
#5  0xb5f7a04f in QThreadPoolPrivate::waitForDone (this=0x8e5ae60, msecs=msecs@entry=-1) at concurrent/qthreadpool.cpp:298
#6  0xb5f7b3e3 in QThreadPool::~QThreadPool (this=0x8e57cb0, __in_chrg=<optimized out>) at concurrent/qthreadpool.cpp:440
#7  0xb5f7b42c in QThreadPool::~QThreadPool (this=0x8e57cb0, __in_chrg=<optimized out>) at concurrent/qthreadpool.cpp:442
#8  0xb5f7bae8 in QGlobalStaticDeleter<QThreadPool>::~QGlobalStaticDeleter (this=0xb6203aa8 <theInstance()::cleanup>, __in_chrg=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qglobal.h:1950
#9  0xb5cb7791 in __run_exit_handlers (status=status@entry=1, listp=0xb5e343e4 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:77
#10 0xb5cb781d in __GI_exit (status=1) at exit.c:99
#11 0xb6666dc8 in qt_xio_errhandler () at kernel/qapplication_x11.cpp:782
#12 0xb713f9f9 in KApplication::xioErrhandler (this=0xbfa315c0, dpy=dpy@entry=0x8764f18) at ../../kdeui/kernel/kapplication.cpp:419
#13 0xb713fab4 in kde_xio_errhandler (dpy=0x8764f18) at ../../kdeui/kernel/kapplication.cpp:126
#14 0xb56bab24 in _XIOError () from /usr/lib/i386-linux-gnu/libX11.so.6
#15 0xb56b829f in _XEventsQueued () from /usr/lib/i386-linux-gnu/libX11.so.6
#16 0xb56941ec in XCheckIfEvent () from /usr/lib/i386-linux-gnu/libX11.so.6
#17 0xb666ac3f in QETWidget::translatePaintEvent (this=this@entry=0x8918f10, event=event@entry=0xbfa3124c) at kernel/qapplication_x11.cpp:5580
#18 0xb667c4da in QApplication::x11ProcessEvent (this=0xbfa315c0, event=event@entry=0xbfa3124c) at kernel/qapplication_x11.cpp:3646
#19 0xb66a8274 in x11EventSourceDispatch (s=0x8735390, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#20 0xb503083e in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#21 0xb5030be8 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#22 0xb5030ca8 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#23 0xb60c68bf in QEventDispatcherGlib::processEvents (this=this@entry=0x8710380, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#24 0xb66a832e in QGuiEventDispatcherGlib::processEvents (this=0x8710380, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#25 0xb60959f3 in QEventLoop::processEvents (this=this@entry=0xbfa31508, flags=...) at kernel/qeventloop.cpp:149
#26 0xb6095d19 in QEventLoop::exec (this=this@entry=0xbfa31508, flags=...) at kernel/qeventloop.cpp:204
#27 0xb609b89e in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1218
#28 0xb65f1974 in QApplication::exec () at kernel/qapplication.cpp:3828
#29 0x0805c48e in main (argc=5, argv=0xbfa31694) at /build/buildd/muon-2.1.3/muon/main.cpp:56

Possible duplicates by query: bug 316246.

Reported using DrKonqi