Application: cantor (0.5)
KDE Platform Version: 4.13.3
Qt Version: 4.8.6
Operating System: Linux 3.15.5-2-ARCH x86_64
Distribution (Platform): Archlinux Packages

-- Information about the crash:
- What I was doing when the application crashed:
In Cantor, choose sage as the backend, and restart it.
- Custom settings of the application:
All settings in Cantor except for line numbers is checked.

The crash can be reproduced every time.

-- Backtrace:
Application: Cantor (cantor), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7ff338b0e780 (LWP 9109))]

Thread 2 (Thread 0x7ff31a78c700 (LWP 9156)):
#0  0x00007ff33589581d in poll () from /usr/lib/libc.so.6
#1  0x00007ff331cc1d64 in ?? () from /usr/lib/libglib-2.0.so.0
#2  0x00007ff331cc1e6c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0x00007ff336cc62c6 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#4  0x00007ff336c9815f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#5  0x00007ff336c98455 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#6  0x00007ff336b947ef in QThread::exec() () from /usr/lib/libQtCore.so.4
#7  0x00007ff336c79943 in ?? () from /usr/lib/libQtCore.so.4
#8  0x00007ff336b96ebf in ?? () from /usr/lib/libQtCore.so.4
#9  0x00007ff333690124 in start_thread () from /usr/lib/libpthread.so.0
#10 0x00007ff33589e4bd in clone () from /usr/lib/libc.so.6

Thread 1 (Thread 0x7ff338b0e780 (LWP 9109)):
[KCrash Handler]
#5  0x00007ff324144f74 in ?? () from /usr/lib/kde4/cantor_sagebackend.so
#6  0x00007ff324141795 in ?? () from /usr/lib/kde4/cantor_sagebackend.so
#7  0x00007ff336cad30a in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/libQtCore.so.4
#8  0x00007ff337114fb5 in KDirWatch::created(QString const&) () from /usr/lib/libkdecore.so.5
#9  0x00007ff337116bb2 in KDirWatch::setCreated(QString const&) () from /usr/lib/libkdecore.so.5
#10 0x00007ff336cb16ae in QObject::event(QEvent*) () from /usr/lib/libQtCore.so.4
#11 0x00007ff336039f0c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#12 0x00007ff33604048d in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#13 0x00007ff33852142a in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#14 0x00007ff336c9958d in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#15 0x00007ff336c9c6dd in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQtCore.so.4
#16 0x00007ff336cc69e3 in ?? () from /usr/lib/libQtCore.so.4
#17 0x00007ff331cc1b84 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#18 0x00007ff331cc1dc8 in ?? () from /usr/lib/libglib-2.0.so.0
#19 0x00007ff331cc1e6c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#20 0x00007ff336cc62a5 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#21 0x00007ff3360d6fb6 in ?? () from /usr/lib/libQtGui.so.4
#22 0x00007ff336c9815f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#23 0x00007ff336c98455 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#24 0x00007ff336c9d719 in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#25 0x0000000000409f87 in ?? ()
#26 0x00007ff3357d5000 in __libc_start_main () from /usr/lib/libc.so.6
#27 0x000000000040a152 in _start ()

Possible duplicates by query: bug 262899, bug 283216, bug 281622.

Report to https://bugs.kde.org/