from PyQt5.QtWidgets import QApplication
app = QApplication([])
Segmentation fault (core dumped)

>>> from PyQt5.QtWidgets import QApplication, QLabel
>>> app = QApplication([])
[New Thread 0x7fffe9fc0700 (LWP 7142)]

Thread 1 "python3" received signal SIGSEGV, Segmentation fault.
0x00007fffee51db28 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
(gdb) bt
#0  0x00007fffee51db28 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#1  0x00007fffee509650 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#2  0x00007fffee509728 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#3  0x00007fffee4fedf9 in QXcbConnection::QXcbConnection(QXcbNativeInterface*, bool, unsigned int, char const*) () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007fffee5024be in QXcbIntegration::QXcbIntegration(QStringList const&, int&, char**) () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#5  0x00007fffee7c562d in QXcbIntegrationPlugin::create(QString const&, QStringList const&, int&, char**) ()
   from /home/manu/.local/lib/python3.6/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so
#6  0x00007ffff44815eb in QPlatformIntegrationFactory::create(QString const&, QStringList const&, int&, char**, QString const&) ()
   from /home/manu/.local/lib/python3.6/site-packages/PyQt5/Qt/lib/libQt5Gui.so.5
#7  0x00007ffff448e8f7 in QGuiApplicationPrivate::createPlatformIntegration() () from /home/manu/.local/lib/python3.6/site-packages/PyQt5/Qt/lib/libQt5Gui.so.5
#8  0x00007ffff448f9dd in QGuiApplicationPrivate::createEventDispatcher() () from /home/manu/.local/lib/python3.6/site-packages/PyQt5/Qt/lib/libQt5Gui.so.5
#9  0x00007ffff3e332ff in QCoreApplicationPrivate::init() () from /home/manu/.local/lib/python3.6/site-packages/PyQt5/Qt/lib/libQt5Core.so.5
#10 0x00007ffff449130b in QGuiApplicationPrivate::init() () from /home/manu/.local/lib/python3.6/site-packages/PyQt5/Qt/lib/libQt5Gui.so.5
#11 0x00007ffff4cda1d9 in QApplicationPrivate::init() () from /home/manu/.local/lib/python3.6/site-packages/PyQt5/Qt/lib/libQt5Widgets.so.5
#12 0x00007ffff5611269 in sipQApplication::sipQApplication(int&, char**, int) () from /home/manu/.local/lib/python3.6/site-packages/PyQt5/QtWidgets.so
#13 0x00007ffff5611339 in init_type_QApplication () from /home/manu/.local/lib/python3.6/site-packages/PyQt5/QtWidgets.so
#14 0x00007fffef551c74 in sipSimpleWrapper_init () from /home/manu/.local/lib/python3.6/site-packages/PyQt5/sip.so
#15 0x0000000000555421 in type_call.lto_priv () at ../Objects/typeobject.c:915
#16 0x00000000005a730c in _PyObject_FastCallDict (kwargs=<optimized out>, nargs=<optimized out>, args=<optimized out>, func=<sip.wrappertype at remote 0xc808b8>)
    at ../Objects/tupleobject.c:131
#17 _PyObject_FastCallKeywords () at ../Objects/abstract.c:2496
#18 0x0000000000503073 in call_function.lto_priv () at ../Python/ceval.c:4861
#19 0x0000000000506859 in _PyEval_EvalFrameDefault () at ../Python/ceval.c:3335
#20 0x0000000000504c28 in PyEval_EvalFrameEx (throwflag=0, f=Frame 0xaeaa18, for file <stdin>, line 1, in <module> ()) at ../Python/ceval.c:4166
#21 _PyEval_EvalCodeWithName.lto_priv.1761 () at ../Python/ceval.c:4166
#22 0x0000000000506393 in PyEval_EvalCodeEx (closure=0x0, kwdefs=0x0, defcount=0, defs=0x0, kwcount=0, kws=0x0, argcount=0, args=0x0, locals=<optimized out>, globals=<optimized out>,
    _co=<optimized out>) at ../Python/ceval.c:4187
#23 PyEval_EvalCode (co=<optimized out>, globals=<optimized out>, locals=<optimized out>) at ../Python/ceval.c:731
#24 0x0000000000634d52 in run_mod () at ../Python/pythonrun.c:1025
#25 0x00000000004a38c5 in PyRun_InteractiveOneObjectEx (fp=fp@entry=0x7ffff7dcfa00 <_IO_2_1_stdin_>, filename=filename@entry='<stdin>', flags=flags@entry=0x7fffffffcdbc)
    at ../Python/pythonrun.c:246
#26 0x00000000004a5cd5 in PyRun_InteractiveLoopFlags (fp=fp@entry=0x7ffff7dcfa00 <_IO_2_1_stdin_>, filename_str=filename_str@entry=0x7541e0 "<stdin>",
    flags=flags@entry=0x7fffffffcdbc) at ../Python/pythonrun.c:114
#27 0x00000000006387b3 in PyRun_AnyFileExFlags () at ../Python/pythonrun.c:75
#28 0x000000000063915a in run_file (p_cf=0x7fffffffcdbc, filename=<optimized out>, fp=<optimized out>) at ../Modules/main.c:340
#29 Py_Main () at ../Modules/main.c:810
#30 0x00000000004a6f10 in main (argc=1, argv=0x7fffffffcfb8) at ../Programs/python.c:69