Bug 1282952

Description of problem:
running gnome-boxes test from upstream:
delete_local_livecd_box
from:
https://github.com/GNOME/gnome-boxes/blob/master/tests/livecd.feature

it's crashing in:
    Then Box "Core-5" "does not" exist      # steps/general.py:18

> /home/test/gnome-boxes/tests/steps/general.py(25)does_box_exists()
(Pdb) s
--Call--
> /usr/lib/python2.7/site-packages/behave/runner.py(206)__getattr__()
-> def __getattr__(self, attr):
(Pdb) s
> /usr/lib/python2.7/site-packages/behave/runner.py(207)__getattr__()
-> if attr[0] == '_':
(Pdb) s
> /usr/lib/python2.7/site-packages/behave/runner.py(209)__getattr__()
-> for frame in self._stack:
(Pdb) s
> /usr/lib/python2.7/site-packages/behave/runner.py(210)__getattr__()
-> if attr in frame:
(Pdb) s
> /usr/lib/python2.7/site-packages/behave/runner.py(211)__getattr__()
-> return frame[attr]
(Pdb) s
--Return--
> /usr/lib/python2.7/site-packages/behave/runner.py(211)__getattr__()-><Accessi...877feb0)>
-> return frame[attr]
(Pdb) s
--Call--
> /usr/lib/python2.7/site-packages/pyatspi/Accessibility.py(48)Accessible_str()
-> def Accessible_str(self):
(Pdb) s
> /usr/lib/python2.7/site-packages/pyatspi/Accessibility.py(55)Accessible_str()
-> try:
(Pdb) s
> /usr/lib/python2.7/site-packages/pyatspi/Accessibility.py(56)Accessible_str()
-> return '[%s | %s]' % (self.getRoleName(), self.name)
(Pdb) s
Segmentation fault (core dumped)

It's 100% reproducible

Version-Release number of selected component:
python-behave-1.2.5-3.fc23

Additional info:
reporter:       libreport-2.6.3
backtrace_rating: 4
cmdline:        /usr/bin/python2 /usr/bin/behave -kt @delete_five_local_livecd_boxes
crash_function: cache_process_children_changed
executable:     /usr/bin/python2.7
global_pid:     8280
kernel:         4.2.5-300.fc23.x86_64
runlevel:       N 5
type:           CCpp
uid:            1000

Truncated backtrace:
Thread no. 1 (10 frames)
 #0 cache_process_children_changed at atspi-event-listener.c:231
 #1 _atspi_dbus_handle_event at atspi-event-listener.c:1054
 #2 process_deferred_message at atspi-misc.c:731
 #3 process_deferred_messages at atspi-misc.c:765
 #5 _atspi_dbus_get_property at atspi-misc.c:1233
 #6 atspi_accessible_get_child_count at atspi-accessible.c:321
 #7 ffi_call_unix64 at ../src/x86/unix64.S:76
 #8 ffi_call at ../src/x86/ffi64.c:525
 #9 pygi_invoke_c_callable at pygi-invoke.c:645
 #10 pygi_function_cache_invoke at pygi-cache.c:820