Qt QTest segmentation fault at end of execution

Question

I have a small test programs that talks to a server backend through a library that I have written. The test uses the QTest framework and runs through a bunch of test cases. The latest version of the test program has started to issue a segmentation fault after all of my tests have run. The output is something like:

********* Start testing of TestSequence *********
Config: Using QtTest library 5.6.1, Qt 5.6.1 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 4.9.1 20140922 (Red Hat 4.9.1-10))

...

Totals: 28 passed, 0 failed, 0 skipped, 0 blacklisted
********* Finished testing of TestSequence *********

RUN FINISHED; Segmentation fault; core dumped; real time: 26s; user: 40ms; system: 290ms

I can get a stack backtrace from the segfault:

#0  0x00007fffe9b3a61e in QDBusMetaType::typeToSignature(int) () from /home/pete/Qt/5.6/gcc_64/plugins/bearer/../../lib/libQt5DBus.so.5
No symbol table info available.
#1  0x00007fffe9b31a9e in qDBusParametersForMethod(QList<QByteArray> const&, QVector<int>&, QString&) () from /home/pete/Qt/5.6/gcc_64/plugins/bearer/../../lib/libQt5DBus.so.5
No symbol table info available.
#2  0x00007fffe9b31fc9 in ?? () from /home/pete/Qt/5.6/gcc_64/plugins/bearer/../../lib/libQt5DBus.so.5
No symbol table info available.
#3  0x00007fffe9aff081 in ?? () from /home/pete/Qt/5.6/gcc_64/plugins/bearer/../../lib/libQt5DBus.so.5
No symbol table info available.
#4  0x00007fffe9aff8bf in ?? () from /home/pete/Qt/5.6/gcc_64/plugins/bearer/../../lib/libQt5DBus.so.5
No symbol table info available.
#5  0x00007fffe9b005c6 in ?? () from /home/pete/Qt/5.6/gcc_64/plugins/bearer/../../lib/libQt5DBus.so.5
No symbol table info available.
#6  0x00007fffe9b115af in ?? () from /home/pete/Qt/5.6/gcc_64/plugins/bearer/../../lib/libQt5DBus.so.5
No symbol table info available.
#7  0x00007ffff626cf7a in QObject::event(QEvent*) () from /home/pete/Qt/5.6/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#8  0x00007ffff6242b6b in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /home/pete/Qt/5.6/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#9  0x00007ffff6245373 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /home/pete/Qt/5.6/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#10 0x00007ffff6291d83 in ?? () from /home/pete/Qt/5.6/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#11 0x00007ffff45f6e04 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#12 0x00007ffff45f7048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#13 0x00007ffff45f70ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#14 0x00007ffff6292177 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/pete/Qt/5.6/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#15 0x00007ffff6240bca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/pete/Qt/5.6/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#16 0x00007ffff607ae4c in QThread::exec() () from /home/pete/Qt/5.6/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#17 0x00007ffff607f769 in ?? () from /home/pete/Qt/5.6/gcc_64/lib/libQt5Core.so.5
No symbol table info available.
#18 0x00007ffff4f19182 in start_thread (arg=0x7fffea796700) at pthread_create.c:312
        __res = <optimised out>
        pd = 0x7fffea796700
        now = <optimised out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140737127212800, -4443015154407963459, 1, 0, 140737127213504, 140737127212800, 4443057989164074173, 4443034828799739069}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimised out>
        pagesize_m1 = <optimised out>
        sp = <optimised out>
        freesize = <optimised out>
        __PRETTY_FUNCTION__ = \"start_thread\"
#19 0x00007ffff57f047d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111
No locals.

This looks like the fault is outside my code, but presumably something I've done has caused it! Any insight from the crowd? Or should I report a bug to Qt?

Answer 1

Your problem seems to be related to this bug that affects Qt 5.6.
As mentioned in the trail of comments, it should have been solved in Qt 5.7. You can also apply a few patches to solve it on version 5.6.
The discussion is dated 6/2016 and lasts at the end of September.