Segmentation fault in /usr/lib/python2.7/dist-packages/sip.so

I got a segmentation fault when running Anki. Backtrace as follows:
#0 sip_api_is_py_method (gil=0x7fffffffcdec, pymc=0x193de4e "", sipSelf=0x2c32202c31353520, cname=0x0, mname=0x7ffff26decb2 <sipStrings_QtGui+78514> "changeEvent")
    at /build/buildd/sip4-4.15.5/siplib/siplib.c:8059
#1 0x00007ffff26b8ce9 in sipQDialog::changeEvent (this=0x193de10, a0=0x7fffffffd140) at sipQtGuipart9.cpp:56529
#2 0x00007ffff16e456f in QWidget::event (this=this@entry=0x193de10, event=event@entry=0x7fffffffd140) at kernel/qwidget.cpp:8768
#3 0x00007ffff26ae0ab in sipQDialog::event (this=0x193de10, a0=0x7fffffffd140) at sipQtGuipart9.cpp:56892
#4 0x00007ffff1694e2c in QApplicationPrivate::notify_helper (this=this@entry=0xa01a60, receiver=receiver@entry=0x193de10, e=e@entry=0x7fffffffd140) at kernel/qapplication.cpp:4567
#5 0x00007ffff169b4a0 in QApplication::notify (this=this@entry=0xe3ee70, receiver=receiver@entry=0x193de10, e=e@entry=0x7fffffffd140) at kernel/qapplication.cpp:4353
#6 0x00007ffff26bf186 in sipQApplication::notify (this=0xe3ee70, a0=0x193de10, a1=0x7fffffffd140) at sipQtGuipart9.cpp:36108
#7 0x00007ffff320d4dd in QCoreApplication::notifyInternal (this=0xe3ee70, receiver=0x193de10, event=event@entry=0x7fffffffd140) at kernel/qcoreapplication.cpp:953
#8 0x00007ffff1693556 in sendSpontaneousEvent (event=event@entry=0x7fffffffd140, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:234
#9 qt_sendSpontaneousEvent (receiver=<optimized out>, event=event@entry=0x7fffffffd140) at kernel/qapplication.cpp:5565
#10 0x00007ffff16e8862 in QKeyMapper::changeKeyboard () at kernel/qkeymapper.cpp:99
#11 0x00007ffff170edd5 in QApplication::x11ProcessEvent (this=0xe3ee70, event=event@entry=0x7fffffffd390) at kernel/qapplication_x11.cpp:3468
#12 0x00007ffff1736b02 in x11EventSourceDispatch (s=0xa02560, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#13 0x00007ffff2dd0e04 in g_main_dispatch (context=0xa02370) at /build/buildd/glib2.0-2.40.2/./glib/gmain.c:3064
#14 g_main_context_dispatch (context=context@entry=0xa02370) at /build/buildd/glib2.0-2.40.2/./glib/gmain.c:3663
#15 0x00007ffff2dd1048 in g_main_context_iterate (context=context@entry=0xa02370, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/buildd/glib2.0-2.40.2/./glib/gmain.c:3734
#16 0x00007ffff2dd10ec in g_main_context_iteration (context=0xa02370, may_block=1) at /build/buildd/glib2.0-2.40.2/./glib/gmain.c:3795
#17 0x00007ffff323a7a1 in QEventDispatcherGlib::processEvents (this=0xa02200, flags=...) at kernel/qeventdispatcher_glib.cpp:434
#18 0x00007ffff1736bb6 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#19 0x00007ffff320c0af in QEventLoop::processEvents (this=this@entry=0x7fffffffd760, flags=...) at kernel/qeventloop.cpp:149
#20 0x00007ffff320c3a5 in QEventLoop::exec (this=this@entry=0x7fffffffd760, flags=...) at kernel/qeventloop.cpp:204
#21 0x00007ffff3211b79 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#22 0x00007ffff169337c in QApplication::exec () at kernel/qapplication.cpp:3828
#23 0x00007ffff267b1f0 in meth_QApplication_exec_ (sipArgs=<optimized out>) at sipQtGuipart9.cpp:37979
#24 0x000000000052c6d5 in PyEval_EvalFrameEx ()
#25 0x000000000052cf32 in PyEval_EvalFrameEx ()
#26 0x000000000052cf32 in PyEval_EvalFrameEx ()
#27 0x000000000055c594 in PyEval_EvalCodeEx ()
#28 0x00000000005b7392 in PyEval_EvalCode ()
#29 0x0000000000469663 in ?? ()
#30 0x00000000004699e3 in PyRun_FileExFlags ()
#31 0x0000000000469f1c in PyRun_SimpleFileExFlags ()
#32 0x000000000046ab81 in Py_Main ()
#33 0x00007ffff7817ec5 in __libc_start_main (main=0x46ac3f <main>, argc=4, argv=0x7fffffffdf38, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffdf28)
    at libc-start.c:287
#34 0x000000000057497e in _start ()