python: Segmentation fault (core dumped)

Question

I have written a Qt application in python using PySide library. When i close it i get Segmentation fault (core dumped)

Backtrace using gdb:

(gdb) backtrace 
#0  0x00007ffff5d19c40 in QObject::staticMetaObject () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#1  0x00007ffff64c4bce in PySide::SignalManager::clear() () from /usr/lib/x86_64-linux-gnu/libpyside-python2.7.so.1.2
#2  0x00007ffff64d1f95 in PySide::destroyQCoreApplication() () from /usr/lib/x86_64-linux-gnu/libpyside-python2.7.so.1.2
#3  0x00007ffff64d2981 in PySide::runCleanupFunctions() () from /usr/lib/x86_64-linux-gnu/libpyside-python2.7.so.1.2
#4  0x00007ffff683ecc5 in ?? () from /usr/lib/python2.7/dist-packages/PySide/QtCore.so
#5  0x000000000052f936 in PyEval_EvalFrameEx ()
#6  0x000000000056d0aa in ?? ()
#7  0x00000000004da29f in PyEval_CallObjectWithKeywords ()
#8  0x000000000042fa19 in Py_Finalize ()
#9  0x000000000042fb7c in Py_Exit ()
#10 0x000000000042fcb9 in ?? ()
#11 0x000000000042ec32 in PyErr_PrintEx ()
#12 0x000000000042f042 in ?? ()
#13 0x000000000046aa09 in Py_Main ()
#14 0x00007ffff7817ec5 in __libc_start_main (main=0x46ac3f <main>, argc=2, argv=0x7fffffffdf58, init=<optimized out>, fini=<optimized out>, 
    rtld_fini=<optimized out>, stack_end=0x7fffffffdf48) at libc-start.c:287
#15 0x000000000057497e in _start ()

Version:

QMake version 3.0
Using Qt version 5.2.1 in /usr/lib/x86_64-linux-gnu
Python 2.7.6
Ubuntu 14.04

How i can solve this?

Answer 1

If this question is still up-to-date, I had the same Problem and solved it today. In my case it was a problem by calling

destroy()

method of my widget directly. Since I had some threads left open it ran into a segfault. As I read right now it is a better practice to emit the close event.

I did now also override the closeEvt() method and checked there if the there is stuff to do before closing the app

##
#  Closes the application
#  ...
def closeEvent(self, event):
    if self.canClose() # Exit the application
        event.accept() 
        logging.debug("Closed App clean")
    else:
        # Do stuff to close the application cleanly
        if canCloseNow:
            event.accept()
        else: 
            # Give user feedbackstuff like opening a save dialog 
            # or some other stuff...
            event.ignore()

I am aware that most possibly there are much more elegant procedures to do this but for me it worked quite well...