Application: systemsettings5 (5.2.2)

Qt Version: 5.4.1
Operating System: Linux 3.19.0-25-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
Here I'm posting a crash concerning the Setting Manager, but this report is the same for lots of KDE apps.
For istance, yesterday Konsole crashed after a clean exit, the day before plasma (I suspect it's network-manager fault, still after a clean exit)

- What I was doing when the application crashed:
Nothing interesting, just tinkering with some settings. Then I pressed the cross button on the top-left so as to close the application, and it crashed.

The backtrace is more or less the same for the other apps quoted above, and all of them refer to a certain error in Qt 5 library.

I'm using Kubuntu 15.04; I installed it just some days after it'd been released (not a really good idea, I know). The problem is likely to be correct if I reinstalled my distro, waited for a new LTS or installed a new clean distro, maybe KDE-centric (like Chakra). In that case, please ignore this report.

The crash can be reproduced every time.

-- Backtrace:
Application: Impostazioni di sistema (systemsettings5), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fa2dbb78780 (LWP 4457))]

Thread 3 (Thread 0x7fa2c937f700 (LWP 4458)):
#0  0x00007fa2d82e68dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fa2d6600b72 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007fa2d660264f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fa2cc13d099 in QXcbEventReader::run (this=0x1feac70) at qxcbconnection.cpp:1105
#4  0x00007fa2d8967b0e in QThreadPrivate::start (arg=0x1feac70) at thread/qthread_unix.cpp:337
#5  0x00007fa2d551a6aa in start_thread (arg=0x7fa2c937f700) at pthread_create.c:333
#6  0x00007fa2d82f1eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fa2b92af700 (LWP 4463)):
#0  0x00007fa2d82e68dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fa2d4ffbebc in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fa2d4ffc242 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fa2a3720af6 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007fa2d5022955 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007fa2d551a6aa in start_thread (arg=0x7fa2b92af700) at pthread_create.c:333
#6  0x00007fa2d82f1eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fa2dbb78780 (LWP 4457)):
[KCrash Handler]
#6  0x00007fa2d73efd6b in QQuickItemPrivate::addToDirtyList() () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007fa2d73efe28 in QQuickItemPrivate::dirty(QQuickItemPrivate::DirtyType) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007fa2d73fa045 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007fa2d8bd773a in QObject::event (this=0x28afe00, e=<optimized out>) at kernel/qobject.cpp:1245
#10 0x00007fa2d73f8b6b in QQuickItem::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#11 0x00007fa2d9991b2c in QApplicationPrivate::notify_helper (this=0x1fbf550, receiver=0x28afe00, e=0x7fa2a8155a10) at kernel/qapplication.cpp:3720
#12 0x00007fa2d9997000 in QApplication::notify (this=0x7ffcbd4ba6e0, receiver=0x28afe00, e=0x7fa2a8155a10) at kernel/qapplication.cpp:3503
#13 0x00007fa2d8ba5c2b in QCoreApplication::notifyInternal (this=0x7ffcbd4ba6e0, receiver=0x28afe00, event=event@entry=0x7fa2a8155a10) at kernel/qcoreapplication.cpp:935
#14 0x00007fa2d8ba7c9b in sendEvent (event=0x7fa2a8155a10, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#15 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x1fbe770) at kernel/qcoreapplication.cpp:1552
#16 0x00007fa2d8ba8298 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1410
#17 0x00007fa2d8bfe843 in postEventSourceDispatch (s=0x202be20) at kernel/qeventdispatcher_glib.cpp:271
#18 0x00007fa2d4ffbc3d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007fa2d4ffbf20 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007fa2d4ffbfcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007fa2d8bfec57 in QEventDispatcherGlib::processEvents (this=0x20283d0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#22 0x00007fa2d8ba33e2 in QEventLoop::exec (this=this@entry=0x7ffcbd4ba5c0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#23 0x00007fa2d8bab02c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#24 0x00007fa2d93cc31c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#25 0x00007fa2d998d7a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#26 0x000000000040eebc in main (argc=1, argv=<optimized out>) at ../../app/main.cpp:54

Reported using DrKonqi