Bug 386992

gdb backtrace of an hanged discover session

$ gdb plasma-discover 20316
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Reading symbols from plasma-discover...Reading symbols from /usr/lib/debug/usr/bin/plasma-discover.debug...done.
done.
Attaching to program: /usr/bin/plasma-discover, process 20316
[New LWP 20317]
[New LWP 20318]
[New LWP 20319]
[New LWP 20321]
[New LWP 20322]
[New LWP 20323]
[New LWP 20324]
[New LWP 20325]
[New LWP 20326]
[New LWP 20327]
[New LWP 20329]
[New LWP 20331]
[New LWP 20332]
[New LWP 20336]
[New LWP 20337]
[New LWP 20342]
[New LWP 20345]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".

warning: the debug information found in "/usr/lib/debug//usr/lib64/libostree-1.so.1.0.0.debug" does not match "/lib64/libostree-1.so.1" (CRC mismatch).

syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
38              cmpq $-4095, %rax       /* Check %rax for error.  */
Missing separate debuginfos, use: dnf debuginfo-install flatpak-libs-0.9.99-1.fc26.x86_64 openssl-libs-1.1.0f-7.fc26.x86_64 ostree-libs-2017.13-2.fc26.x86_64
(gdb) thread apply all backtrace

Thread 18 (Thread 0x7f1c1b7fe700 (LWP 20345)):
#0  0x00007f1c8235590b in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f678d2397c) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f1c8235590b in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f678d23928, cond=0x55f678d23950) at pthread_cond_wait.c:502
#2  0x00007f1c8235590b in __pthread_cond_wait (cond=0x55f678d23950, mutex=0x55f678d23928) at pthread_cond_wait.c:655
#3  0x00007f1c5345df7b in cnd_wait (mtx=0x55f678d23928, cond=0x55f678d23950) at ../../include/c11/threads_posix.h:159
#4  0x00007f1c5345df7b in util_queue_thread_func (input=input@entry=0x55f678bae3c0) at u_queue.c:158
#5  0x00007f1c5345de97 in impl_thrd_routine (p=<optimized out>) at ../../include/c11/threads_posix.h:87
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c1b7fe700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 17 (Thread 0x7f1c1ffff700 (LWP 20342)):
#0  0x00007f1c837e47b9 in syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007f1c843ff405 in _q_futex (timeout=0x0, val=3, op=0, addr=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex_linux.cpp:123
#2  0x00007f1c843ff405 in lockInternal_helper<false> (timeout=-1, elapsedTimer=0x0, d_ptr=...) at thread/qmutex_linux.cpp:164
#3  0x00007f1c843ff405 in QBasicMutex::lockInternal() (this=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex_linux.cpp:180
#4  0x00007f1c843ff5eb in QMutex::lock() (this=this@entry=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex.cpp:230
#5  0x00007f1c845d67fa in QMutexLocker::QMutexLocker(QBasicMutex*) (m=<optimized out>, this=<synthetic pointer>) at ../../src/corelib/thread/qmutex.h:137
#6  0x00007f1c845d67fa in QMetaObjectPrivate::disconnect(QObject const*, int, QMetaObject const*, QObject const*, int, void**, QMetaObjectPrivate::DisconnectType) (sender=sender@entry=0x7f1c0c229a70, signal_index=signal_index@entry=-1, smeta=0x7f1c84bdaea0 <QNativeSocketEngine::staticMetaObject>, receiver=receiver@entry=0x0, method_index=method_index@entry=-1, slot=slot@entry=0x0, disconnectType=QMetaObjectPrivate::DisconnectAll) at kernel/qobject.cpp:3391
#7  0x00007f1c845d7a00 in QObject::disconnect(QObject const*, char const*, QObject const*, char const*) (sender=0x7f1c0c229a70, signal=signal@entry=0x0, receiver=receiver@entry=0x0, method=method@entry=0x0) at kernel/qobject.cpp:2980
---Type <return> to continue, or q <return> to quit---
#8  0x00007f1c84b4997b in QObject::disconnect(char const*, QObject const*, char const*) const (member=0x0, receiver=0x0, signal=0x0, this=<optimized out>)
    at ../../src/corelib/kernel/qobject.h:334
#9  0x00007f1c84b4997b in QAbstractSocketPrivate::resetSocketLayer() (this=this@entry=0x7f1c0c2591e0) at socket/qabstractsocket.cpp:598
#10 0x00007f1c84b4a468 in QAbstractSocketPrivate::readFromSocket() (this=this@entry=0x7f1c0c2591e0) at socket/qabstractsocket.cpp:1285
#11 0x00007f1c84b4a53e in QAbstractSocketPrivate::canReadNotification() (this=0x7f1c0c2591e0) at socket/qabstractsocket.cpp:703
#12 0x00007f1c84b552d1 in QReadNotifier::event(QEvent*) (this=<optimized out>, e=<optimized out>) at socket/qnativesocketengine.cpp:1209
#13 0x00007f1c855db5dc in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=
    0x55f675d7a9c0, receiver=receiver@entry=0x7f1c0c0090d0, e=e@entry=0x7f1c1fffead0) at kernel/qapplication.cpp:3799
#14 0x00007f1c855e2c74 in QApplication::notify(QObject*, QEvent*) (this=0x7ffccb131f70, receiver=0x7f1c0c0090d0, e=0x7f1c1fffead0) at kernel/qapplication.cpp:3556
#15 0x00007f1c845ab627 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x7f1c0c0090d0, event=event@entry=0x7f1c1fffead0)
    at kernel/qcoreapplication.cpp:988
#16 0x00007f1c845fa77f in QCoreApplication::sendEvent(QObject*, QEvent*) (event=0x7f1c1fffead0, receiver=<optimized out>)
    at ../../src/corelib/kernel/qcoreapplication.h:231
#17 0x00007f1c845fa77f in socketNotifierSourceDispatch(GSource*, GSourceFunc, gpointer) (source=0x7f1c0c001810) at kernel/qeventdispatcher_glib.cpp:106
#18 0x00007f1c7caf9247 in g_main_dispatch (context=0x7f1c0c0016d0) at gmain.c:3234
#19 0x00007f1c7caf9247 in g_main_context_dispatch (context=context@entry=0x7f1c0c0016d0) at gmain.c:3899
#20 0x00007f1c7caf95e8 in g_main_context_iterate (context=context@entry=0x7f1c0c0016d0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at gmain.c:3972
#21 0x00007f1c7caf967c in g_main_context_iteration (context=0x7f1c0c0016d0, may_block=may_block@entry=1) at gmain.c:4033
#22 0x00007f1c845f9e4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f1c0c001ac0, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#23 0x00007f1c845aa60a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f1c1fffecf0, flags=..., flags@entry=...)
    at kernel/qeventloop.cpp:212
---Type <return> to continue, or q <return> to quit---
#24 0x00007f1c8440299a in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:507
#25 0x00007f1c84406c9e in QThreadPrivate::start(void*) (arg=0x55f678c88dc0) at thread/qthread_unix.cpp:368
#26 0x00007f1c8234f36d in start_thread (arg=0x7f1c1ffff700) at pthread_create.c:456
#27 0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 16 (Thread 0x7f1c2ed19700 (LWP 20337)):
#0  0x00007f1c837ddd2d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1c7caf9569 in g_main_context_poll (priority=<optimized out>, n_fds=2, fds=0x7f1c200010c0, timeout=<optimized out>, context=0x55f676684bd0)
    at gmain.c:4271
#2  0x00007f1c7caf9569 in g_main_context_iterate (context=0x55f676684bd0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3967
#3  0x00007f1c7caf9902 in g_main_loop_run (loop=0x55f676686650) at gmain.c:4168
#4  0x00007f1c6f456cb6 in gdbus_shared_thread_func (user_data=0x55f6766865a0) at gdbusprivate.c:252
#5  0x00007f1c7cb20536 in g_thread_proxy (data=0x55f67667aca0) at gthread.c:784
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c2ed19700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 15 (Thread 0x7f1c2f51a700 (LWP 20336)):
#0  0x00007f1c837ddd2d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1c7caf9569 in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7f1c280008c0, timeout=<optimized out>, context=0x55f676657990)
    at gmain.c:4271
#2  0x00007f1c7caf9569 in g_main_context_iterate (context=context@entry=0x55f676657990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at gmain.c:3967
#3  0x00007f1c7caf967c in g_main_context_iteration (context=0x55f676657990, may_block=may_block@entry=1) at gmain.c:4033
---Type <return> to continue, or q <return> to quit---
#4  0x00007f1c7caf96c1 in glib_worker_main (data=<optimized out>) at gmain.c:5824
#5  0x00007f1c7cb20536 in g_thread_proxy (data=0x55f67667ac00) at gthread.c:784
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c2f51a700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 14 (Thread 0x7f1c46fc8700 (LWP 20332)):
#0  0x00007f1c837e47b9 in syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007f1c843ff405 in _q_futex (timeout=0x0, val=3, op=0, addr=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex_linux.cpp:123
#2  0x00007f1c843ff405 in lockInternal_helper<false> (timeout=-1, elapsedTimer=0x0, d_ptr=...) at thread/qmutex_linux.cpp:164
#3  0x00007f1c843ff405 in QBasicMutex::lockInternal() (this=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex_linux.cpp:180
#4  0x00007f1c843ff5eb in QMutex::lock() (this=this@entry=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex.cpp:230
#5  0x00007f1c845da1d9 in QOrderedMutexLocker::relock(QMutex*, QMutex*) (mtx2=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>, mtx1=0x7f1c847ecef0 <_q_ObjectMutexPool+752>)
    at ../../src/corelib/thread/qorderedmutexlocker_p.h:108
#6  0x00007f1c845da1d9 in QObject::~QObject() (this=<optimized out>, __in_chrg=<optimized out>) at kernel/qobject.cpp:1007
#7  0x00007f1c84b135c7 in QNetworkAccessCachedHttpConnection::~QNetworkAccessCachedHttpConnection() (this=0x7f1c3800a4d0, __in_chrg=<optimized out>)
    at access/qhttpthreaddelegate.cpp:175
#8  0x00007f1c84b135c7 in QNetworkAccessCachedHttpConnection::~QNetworkAccessCachedHttpConnection() (this=0x7f1c3800a4d0, __in_chrg=<optimized out>)
    at access/qhttpthreaddelegate.cpp:175
#9  0x00007f1c84ae837e in QNetworkAccessCache::timerEvent(QTimerEvent*) (this=0x7f1c38002f70) at access/qnetworkaccesscache.cpp:229
#10 0x00007f1c845d388b in QObject::event(QEvent*) (this=0x7f1c38002f70, e=<optimized out>) at kernel/qobject.cpp:1285
#11 0x00007f1c855db5dc in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0x55f675d7a9c0, receiver=receiver@entry=0x7f1c38002f70, e=e@entry=0x7f1c46fc7aa0) at kernel/qapplication.cpp:3799
#12 0x00007f1c855e2c74 in QApplication::notify(QObject*, QEvent*) (this=0x7ffccb131f70, receiver=0x7f1c38002f70, e=0x7f1c46fc7aa0) at kernel/qapplication.cpp:3556
---Type <return> to continue, or q <return> to quit---
#13 0x00007f1c845ab627 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x7f1c38002f70, event=event@entry=0x7f1c46fc7aa0)
    at kernel/qcoreapplication.cpp:988
#14 0x00007f1c845f948b in QCoreApplication::sendEvent(QObject*, QEvent*) (event=0x7f1c46fc7aa0, receiver=<optimized out>)
    at ../../src/corelib/kernel/qcoreapplication.h:231
#15 0x00007f1c845f948b in QTimerInfoList::activateTimers() (this=0x7f1c38002cd0) at kernel/qtimerinfo_unix.cpp:644
#16 0x00007f1c845f99d1 in timerSourceDispatch(GSource*, GSourceFunc, gpointer) (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:182
#17 0x00007f1c7caf9247 in g_main_dispatch (context=0x7f1c38000990) at gmain.c:3234
#18 0x00007f1c7caf9247 in g_main_context_dispatch (context=context@entry=0x7f1c38000990) at gmain.c:3899
#19 0x00007f1c7caf95e8 in g_main_context_iterate (context=context@entry=0x7f1c38000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at gmain.c:3972
#20 0x00007f1c7caf967c in g_main_context_iteration (context=0x7f1c38000990, may_block=may_block@entry=1) at gmain.c:4033
#21 0x00007f1c845f9e4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f1c380008c0, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#22 0x00007f1c845aa60a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f1c46fc7cf0, flags=..., flags@entry=...)
    at kernel/qeventloop.cpp:212
#23 0x00007f1c8440299a in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:507
#24 0x00007f1c84406c9e in QThreadPrivate::start(void*) (arg=0x55f67658f780) at thread/qthread_unix.cpp:368
#25 0x00007f1c8234f36d in start_thread (arg=0x7f1c46fc8700) at pthread_create.c:456
#26 0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 13 (Thread 0x7f1c4be43700 (LWP 20331)):
#0  0x00007f1c837ddd2d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1c7caf9569 in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7f1c40003070, timeout=<optimized out>, context=0x7f1c40000990)
---Type <return> to continue, or q <return> to quit---
    at gmain.c:4271
#2  0x00007f1c7caf9569 in g_main_context_iterate (context=context@entry=0x7f1c40000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at gmain.c:3967
#3  0x00007f1c7caf967c in g_main_context_iteration (context=0x7f1c40000990, may_block=may_block@entry=1) at gmain.c:4033
#4  0x00007f1c845f9e4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f1c400008c0, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#5  0x00007f1c845aa60a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f1c4be42cf0, flags=..., flags@entry=...)
    at kernel/qeventloop.cpp:212
#6  0x00007f1c8440299a in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:507
#7  0x00007f1c84406c9e in QThreadPrivate::start(void*) (arg=0x55f676376410) at thread/qthread_unix.cpp:368
#8  0x00007f1c8234f36d in start_thread (arg=0x7f1c4be43700) at pthread_create.c:456
#9  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 12 (Thread 0x7f1c4cba4700 (LWP 20329)):
#0  0x00007f1c837ddd2d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1c7caf9569 in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7f1c540013c0, timeout=<optimized out>, context=0x7f1c54002ed0)
    at gmain.c:4271
#2  0x00007f1c7caf9569 in g_main_context_iterate (context=context@entry=0x7f1c54002ed0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at gmain.c:3967
#3  0x00007f1c7caf967c in g_main_context_iteration (context=0x7f1c54002ed0, may_block=may_block@entry=1) at gmain.c:4033
#4  0x00007f1c845f9e4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f1c54002e00, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#5  0x00007f1c845aa60a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f1c4cba3c80, flags=..., flags@entry=...)
---Type <return> to continue, or q <return> to quit---
    at kernel/qeventloop.cpp:212
#6  0x00007f1c8440299a in QThread::exec() (this=this@entry=0x55f676298320) at thread/qthread.cpp:507
#7  0x00007f1c87c8bff6 in QQuickPixmapReader::run() (this=0x55f676298320) at util/qquickpixmapcache.cpp:822
#8  0x00007f1c84406c9e in QThreadPrivate::start(void*) (arg=0x55f676298320) at thread/qthread_unix.cpp:368
#9  0x00007f1c8234f36d in start_thread (arg=0x7f1c4cba4700) at pthread_create.c:456
#10 0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 11 (Thread 0x7f1c4d3a5700 (LWP 20327)):
#0  0x00007f1c8235590b in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f675fed8b0) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f1c8235590b in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f675fed860, cond=0x55f675fed888) at pthread_cond_wait.c:502
#2  0x00007f1c8235590b in __pthread_cond_wait (cond=0x55f675fed888, mutex=0x55f675fed860) at pthread_cond_wait.c:655
#3  0x00007f1c5345df7b in cnd_wait (mtx=0x55f675fed860, cond=0x55f675fed888) at ../../include/c11/threads_posix.h:159
#4  0x00007f1c5345df7b in util_queue_thread_func (input=input@entry=0x55f675fe25e0) at u_queue.c:158
#5  0x00007f1c5345de97 in impl_thrd_routine (p=<optimized out>) at ../../include/c11/threads_posix.h:87
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c4d3a5700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 10 (Thread 0x7f1c4dba6700 (LWP 20326)):
#0  0x00007f1c8235590b in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f675fed8b4) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f1c8235590b in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f675fed860, cond=0x55f675fed888) at pthread_cond_wait.c:502
#2  0x00007f1c8235590b in __pthread_cond_wait (cond=0x55f675fed888, mutex=0x55f675fed860) at pthread_cond_wait.c:655
#3  0x00007f1c5345df7b in cnd_wait (mtx=0x55f675fed860, cond=0x55f675fed888) at ../../include/c11/threads_posix.h:159
#4  0x00007f1c5345df7b in util_queue_thread_func (input=input@entry=0x55f67607e9d0) at u_queue.c:158
---Type <return> to continue, or q <return> to quit---
#5  0x00007f1c5345de97 in impl_thrd_routine (p=<optimized out>) at ../../include/c11/threads_posix.h:87
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c4dba6700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 9 (Thread 0x7f1c4e3a7700 (LWP 20325)):
#0  0x00007f1c8235590b in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f675fed7cc) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f1c8235590b in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f675fed778, cond=0x55f675fed7a0) at pthread_cond_wait.c:502
#2  0x00007f1c8235590b in __pthread_cond_wait (cond=0x55f675fed7a0, mutex=0x55f675fed778) at pthread_cond_wait.c:655
#3  0x00007f1c5345df7b in cnd_wait (mtx=0x55f675fed778, cond=0x55f675fed7a0) at ../../include/c11/threads_posix.h:159
#4  0x00007f1c5345df7b in util_queue_thread_func (input=input@entry=0x55f675fb8880) at u_queue.c:158
#5  0x00007f1c5345de97 in impl_thrd_routine (p=<optimized out>) at ../../include/c11/threads_posix.h:87
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c4e3a7700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 8 (Thread 0x7f1c4eba8700 (LWP 20324)):
#0  0x00007f1c8235590b in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f675fed7cc) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f1c8235590b in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f675fed778, cond=0x55f675fed7a0) at pthread_cond_wait.c:502
#2  0x00007f1c8235590b in __pthread_cond_wait (cond=0x55f675fed7a0, mutex=0x55f675fed778) at pthread_cond_wait.c:655
#3  0x00007f1c5345df7b in cnd_wait (mtx=0x55f675fed778, cond=0x55f675fed7a0) at ../../include/c11/threads_posix.h:159
#4  0x00007f1c5345df7b in util_queue_thread_func (input=input@entry=0x55f675fb8650) at u_queue.c:158
#5  0x00007f1c5345de97 in impl_thrd_routine (p=<optimized out>) at ../../include/c11/threads_posix.h:87
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c4eba8700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97
---Type <return> to continue, or q <return> to quit---

Thread 7 (Thread 0x7f1c4f3a9700 (LWP 20323)):
#0  0x00007f1c8235590b in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f675fed7cc) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f1c8235590b in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f675fed778, cond=0x55f675fed7a0) at pthread_cond_wait.c:502
#2  0x00007f1c8235590b in __pthread_cond_wait (cond=0x55f675fed7a0, mutex=0x55f675fed778) at pthread_cond_wait.c:655
#3  0x00007f1c5345df7b in cnd_wait (mtx=0x55f675fed778, cond=0x55f675fed7a0) at ../../include/c11/threads_posix.h:159
#4  0x00007f1c5345df7b in util_queue_thread_func (input=input@entry=0x55f676074cd0) at u_queue.c:158
#5  0x00007f1c5345de97 in impl_thrd_routine (p=<optimized out>) at ../../include/c11/threads_posix.h:87
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c4f3a9700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 6 (Thread 0x7f1c4fbaa700 (LWP 20322)):
#0  0x00007f1c8235590b in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f675fe21f0) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007f1c8235590b in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f675fe21a0, cond=0x55f675fe21c8) at pthread_cond_wait.c:502
#2  0x00007f1c8235590b in __pthread_cond_wait (cond=0x55f675fe21c8, mutex=0x55f675fe21a0) at pthread_cond_wait.c:655
#3  0x00007f1c5345df7b in cnd_wait (mtx=0x55f675fe21a0, cond=0x55f675fe21c8) at ../../include/c11/threads_posix.h:159
#4  0x00007f1c5345df7b in util_queue_thread_func (input=input@entry=0x55f67607ea40) at u_queue.c:158
#5  0x00007f1c5345de97 in impl_thrd_routine (p=<optimized out>) at ../../include/c11/threads_posix.h:87
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c4fbaa700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 5 (Thread 0x7f1c5e874700 (LWP 20321)):
#0  0x00007f1c8235590b in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55f675fee368) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
---Type <return> to continue, or q <return> to quit---
#1  0x00007f1c8235590b in __pthread_cond_wait_common (abstime=0x0, mutex=0x55f675fee318, cond=0x55f675fee340) at pthread_cond_wait.c:502
#2  0x00007f1c8235590b in __pthread_cond_wait (cond=0x55f675fee340, mutex=0x55f675fee318) at pthread_cond_wait.c:655
#3  0x00007f1c5345df7b in cnd_wait (mtx=0x55f675fee318, cond=0x55f675fee340) at ../../include/c11/threads_posix.h:159
#4  0x00007f1c5345df7b in util_queue_thread_func (input=input@entry=0x55f675f431b0) at u_queue.c:158
#5  0x00007f1c5345de97 in impl_thrd_routine (p=<optimized out>) at ../../include/c11/threads_posix.h:87
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c5e874700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 4 (Thread 0x7f1c652ae700 (LWP 20319)):
#0  0x00007f1c837ddd2d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1c7caf9569 in g_main_context_poll (priority=<optimized out>, n_fds=1, fds=0x7f1c58002e70, timeout=<optimized out>, context=0x7f1c58000990)
    at gmain.c:4271
#2  0x00007f1c7caf9569 in g_main_context_iterate (context=context@entry=0x7f1c58000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at gmain.c:3967
#3  0x00007f1c7caf967c in g_main_context_iteration (context=0x7f1c58000990, may_block=may_block@entry=1) at gmain.c:4033
#4  0x00007f1c845f9e4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f1c580008c0, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#5  0x00007f1c845aa60a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f1c652adcd0, flags=..., flags@entry=...)
    at kernel/qeventloop.cpp:212
#6  0x00007f1c8440299a in QThread::exec() (this=this@entry=0x55f675e5ca70) at thread/qthread.cpp:507
#7  0x00007f1c84eab9b5 in QQmlThreadPrivate::run() (this=0x55f675e5ca70) at qml/ftw/qqmlthread.cpp:147
#8  0x00007f1c84406c9e in QThreadPrivate::start(void*) (arg=0x55f675e5ca70) at thread/qthread_unix.cpp:368
#9  0x00007f1c8234f36d in start_thread (arg=0x7f1c652ae700) at pthread_create.c:456
---Type <return> to continue, or q <return> to quit---
#10 0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 3 (Thread 0x7f1c664bf700 (LWP 20318)):
#0  0x00007f1c837ddd2d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1c7caf9569 in g_main_context_poll (priority=<optimized out>, n_fds=4, fds=0x7f1c6000f600, timeout=<optimized out>, context=0x7f1c60000990)
    at gmain.c:4271
#2  0x00007f1c7caf9569 in g_main_context_iterate (context=context@entry=0x7f1c60000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at gmain.c:3967
#3  0x00007f1c7caf967c in g_main_context_iteration (context=0x7f1c60000990, may_block=may_block@entry=1) at gmain.c:4033
#4  0x00007f1c845f9e4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7f1c600008c0, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#5  0x00007f1c845aa60a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7f1c664becb0, flags=..., flags@entry=...)
    at kernel/qeventloop.cpp:212
#6  0x00007f1c8440299a in QThread::exec() (this=this@entry=0x7f1c8879c060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>)
    at thread/qthread.cpp:507
#7  0x00007f1c88729a39 in QDBusConnectionManager::run() (this=0x7f1c8879c060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>)
    at qdbusconnection.cpp:178
#8  0x00007f1c84406c9e in QThreadPrivate::start(void*) (arg=0x7f1c8879c060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>)
    at thread/qthread_unix.cpp:368
#9  0x00007f1c8234f36d in start_thread (arg=0x7f1c664bf700) at pthread_create.c:456
#10 0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 2 (Thread 0x7f1c6eae0700 (LWP 20317)):
---Type <return> to continue, or q <return> to quit---
#0  0x00007f1c837ddd2d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f1c7c3f7c97 in poll (__timeout=-1, __nfds=1, __fds=0x7f1c6eadfbf0) at /usr/include/bits/poll2.h:46
#2  0x00007f1c7c3f7c97 in _xcb_conn_wait (c=c@entry=0x55f675db7fb0, cond=cond@entry=0x55f675db7ff0, vector=vector@entry=0x0, count=count@entry=0x0)
    at xcb_conn.c:479
#3  0x00007f1c7c3f9a8a in xcb_wait_for_event (c=0x55f675db7fb0) at xcb_in.c:693
#4  0x00007f1c73196ba9 in QXcbEventReader::run() (this=0x55f675dcb000) at qxcbconnection.cpp:1343
#5  0x00007f1c84406c9e in QThreadPrivate::start(void*) (arg=0x55f675dcb000) at thread/qthread_unix.cpp:368
#6  0x00007f1c8234f36d in start_thread (arg=0x7f1c6eae0700) at pthread_create.c:456
#7  0x00007f1c837e9e1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97

Thread 1 (Thread 0x7f1c8862f8c0 (LWP 20316)):
#0  0x00007f1c837e47b9 in syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007f1c843ff405 in _q_futex (timeout=0x0, val=3, op=0, addr=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex_linux.cpp:123
#2  0x00007f1c843ff405 in lockInternal_helper<false> (timeout=-1, elapsedTimer=0x0, d_ptr=...) at thread/qmutex_linux.cpp:164
#3  0x00007f1c843ff405 in QBasicMutex::lockInternal() (this=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex_linux.cpp:180
#4  0x00007f1c843ff5eb in QMutex::lock() (this=this@entry=0x7f1c847ecdb8 <_q_ObjectMutexPool+440>) at thread/qmutex.cpp:230
#5  0x00007f1c845d67fa in QMutexLocker::QMutexLocker(QBasicMutex*) (m=<optimized out>, this=<synthetic pointer>) at ../../src/corelib/thread/qmutex.h:137
#6  0x00007f1c845d67fa in QMetaObjectPrivate::disconnect(QObject const*, int, QMetaObject const*, QObject const*, int, void**, QMetaObjectPrivate::DisconnectType) (sender=sender@entry=0x55f67961b230, signal_index=signal_index@entry=10, smeta=0x7f1c44b2cd60 <OrgFreedesktopPackageKitTransactionInterface::staticMetaObject>, receiver=receiver@entry=0x55f679bded80, method_index=method_index@entry=39, slot=slot@entry=0x0, disconnectType=QMetaObjectPrivate::DisconnectAll)
    at kernel/qobject.cpp:3391
#7  0x00007f1c845d7968 in QObject::disconnect(QObject const*, char const*, QObject const*, char const*) (sender=0x55f67961b230, signal=0x55f679852769 "Finished(uint,uint)", signal@entry=0x7f1c4491a520 "2Finished(uint,uint)", receiver=receiver@entry=0x55f679bded80, method=0x55f679aa75e9 "finished(uint,uint)")
---Type <return> to continue, or q <return> to quit---
    at kernel/qobject.cpp:2991
#8  0x00007f1c44904f45 in QObject::disconnect(char const*, QObject const*, char const*) const (member=<optimized out>, receiver=0x55f679bded80, signal=0x7f1c4491a520 "2Finished(uint,uint)", this=<optimized out>) at /usr/include/qt5/QtCore/qobject.h:334
#9  0x00007f1c44904f45 in PackageKit::TransactionPrivate::setupSignal(QString const&, bool) (this=this@entry=0x55f67a0454e0, signal=..., connect=connect@entry=false) at /usr/src/debug/PackageKit-Qt-0.9.5/src/transaction.cpp:157
#10 0x00007f1c449060d5 in PackageKit::Transaction::disconnectNotify(char const*) (this=<optimized out>, signal=0x55f679aa7cc8 "2finished(PackageKit::Transaction::Exit,uint)") at /usr/src/debug/PackageKit-Qt-0.9.5/src/transaction.cpp:77
#11 0x00007f1c449049e7 in PackageKit::Transaction::disconnectNotify(QMetaMethod const&) (this=0x55f679bded80, signal=...)
    at /usr/src/debug/PackageKit-Qt-0.9.5/src/transaction.cpp:86
#12 0x00007f1c845da1c0 in QObject::~QObject() (this=<optimized out>, __in_chrg=<optimized out>) at kernel/qobject.cpp:1004
#13 0x00007f1c87951599 in ResultsStream::~ResultsStream() (this=0x55f67953e130, __in_chrg=<optimized out>)
    at /usr/src/debug/discover-5.10.5/libdiscover/resources/AbstractResourcesBackend.cpp:64
#14 0x00007f1c845d38f8 in QObject::event(QEvent*) (this=0x55f67953e130, e=<optimized out>) at kernel/qobject.cpp:1254
#15 0x00007f1c855db5dc in QApplicationPrivate::notify_helper(QObject*, QEvent*) (this=this@entry=0x55f675d7a9c0, receiver=receiver@entry=0x55f67953e130, e=e@entry=0x55f67a974aa0) at kernel/qapplication.cpp:3799
#16 0x00007f1c855e2c74 in QApplication::notify(QObject*, QEvent*) (this=0x7ffccb131f70, receiver=0x55f67953e130, e=0x55f67a974aa0) at kernel/qapplication.cpp:3556
#17 0x00007f1c845ab627 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x55f67953e130, event=event@entry=0x55f67a974aa0)
    at kernel/qcoreapplication.cpp:988
#18 0x00007f1c845ad85b in QCoreApplication::sendEvent(QObject*, QEvent*) (event=0x55f67a974aa0, receiver=<optimized out>) at kernel/qcoreapplication.h:231
#19 0x00007f1c845ad85b in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x55f675d79f40) at kernel/qcoreapplication.cpp:1649
#20 0x00007f1c845add68 in QCoreApplication::sendPostedEvents(QObject*, int) (receiver=receiver@entry=0x0, event_type=event_type@entry=0)
    at kernel/qcoreapplication.cpp:1503
---Type <return> to continue, or q <return> to quit---
#21 0x00007f1c845f9dd3 in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=0x55f675e03590) at kernel/qeventdispatcher_glib.cpp:276
#22 0x00007f1c7caf9247 in g_main_dispatch (context=0x7f1c680016f0) at gmain.c:3234
#23 0x00007f1c7caf9247 in g_main_context_dispatch (context=context@entry=0x7f1c680016f0) at gmain.c:3899
#24 0x00007f1c7caf95e8 in g_main_context_iterate (context=context@entry=0x7f1c680016f0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at gmain.c:3972
#25 0x00007f1c7caf967c in g_main_context_iteration (context=0x7f1c680016f0, may_block=may_block@entry=1) at gmain.c:4033
#26 0x00007f1c845f9e4f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x55f675e1fa20, flags=...)
    at kernel/qeventdispatcher_glib.cpp:423
#27 0x00007f1c845aa60a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ffccb131eb0, flags=..., flags@entry=...)
    at kernel/qeventloop.cpp:212
#28 0x00007f1c845b227c in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1261
#29 0x000055f674880750 in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/discover-5.10.5/discover/main.cpp:151
(gdb)