Application: okular (0.24.2)
KDE Platform Version: 4.14.16
Qt Version: 4.8.7
Operating System: Linux 4.13.0-39-generic x86_64
Distribution: Ubuntu 16.04.4 LTS

-- Information about the crash:
Reproduce:
* Compile a latex file with lualatex (tikt + Beamer + pythontex)
* Open generated PDF file in Okular
* Keep Okular open
* recompile the latex file

The crash can be reproduced every time.

-- Backtrace:
Application: Okular (okular), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f17f94d5900 (LWP 12454))]

Thread 2 (Thread 0x7f17e0a48700 (LWP 12457)):
#0  0x00007f17f644174d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f17f351938c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f17f351949c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f17f6ed02ce in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007f17f6e9e18f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#5  0x00007f17f6e9e4f5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#6  0x00007f17f6d8d549 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#7  0x00007f17f6e7e223 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#8  0x00007f17f6d8fe3c in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#9  0x00007f17f3a006ba in start_thread (arg=0x7f17e0a48700) at pthread_create.c:333
#10 0x00007f17f644d41d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f17f94d5900 (LWP 12454)):
[KCrash Handler]
#6  0x000000000264f520 in ?? ()
#7  0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#8  0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#9  0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#10 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#11 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#12 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#13 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#14 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#15 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#16 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#17 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#18 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#19 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#20 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#21 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#22 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#23 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#24 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#25 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#26 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#27 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#28 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#29 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#30 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#31 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#32 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#33 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#34 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#35 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#36 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#37 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#38 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#39 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#40 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#41 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#42 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#43 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#44 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#45 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#46 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#47 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#48 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#49 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#50 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#51 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#52 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#53 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#54 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#55 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#56 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#57 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#58 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#59 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#60 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#61 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#62 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#63 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#64 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#65 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#66 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#67 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#68 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#69 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#70 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#71 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#72 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#73 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#74 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#75 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#76 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#77 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#78 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#79 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#80 0x00007f17e70f1bc5 in _synctex_free_input () from /usr/lib/libokularcore.so.7
#81 0x00007f17e70f6e7f in synctex_scanner_free () from /usr/lib/libokularcore.so.7
#82 0x00007f17e70ba744 in Okular::Document::closeDocument() () from /usr/lib/libokularcore.so.7
#83 0x00007f17e73927b4 in Okular::Part::closeUrl(bool) () from /usr/lib/kde4/okularpart.so
#84 0x00007f17e738f88e in Okular::Part::slotDoFileDirty() () from /usr/lib/kde4/okularpart.so
#85 0x00007f17e739a595 in ?? () from /usr/lib/kde4/okularpart.so
#86 0x00007f17f6eb4010 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#87 0x00007f17f6eb9c83 in QObject::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#88 0x00007f17f78affdc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#89 0x00007f17f78b6f16 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#90 0x00007f17f861564a in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#91 0x00007f17f6e9f90d in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#92 0x00007f17f6ed2780 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#93 0x00007f17f6ecf929 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#94 0x00007f17f3519197 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#95 0x00007f17f35193f0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#96 0x00007f17f351949c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#97 0x00007f17f6ed02ae in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#98 0x00007f17f795d616 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#99 0x00007f17f6e9e18f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#100 0x00007f17f6e9e4f5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#101 0x00007f17f6ea44b9 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#102 0x0000000000409858 in ?? ()
#103 0x00007f17f6366830 in __libc_start_main (main=0x409410, argc=2, argv=0x7ffda1cd8b38, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffda1cd8b28) at ../csu/libc-start.c:291
#104 0x000000000040b489 in _start ()

Reported using DrKonqi