Random Watchdog failures: KeyError

01:55:22 [INFO]      [exec] ======================================================================
01:55:22 [INFO]      [exec] ERROR: test_synchronize_deep_folders (nxdrive.tests.test_integration_synchronization.TestIntegrationSynchronization)
01:55:22 [INFO]      [exec] ----------------------------------------------------------------------
01:55:22 [INFO]      [exec] Traceback (most recent call last):
01:55:22 [INFO]      [exec]   File "/Users/hudson/tmp/workspace/FT-nuxeo-drive-master-osx/nuxeo-drive-client/nxdrive/tests/common.py", line 163, in tearDown
01:55:22 [INFO]      [exec]     observer.stop()
01:55:22 [INFO]      [exec]   File "/usr/local/lib/python2.7/site-packages/watchdog/utils/__init__.py", line 113, in stop
01:55:22 [INFO]      [exec]     self.on_thread_stop()
01:55:22 [INFO]      [exec]   File "/usr/local/lib/python2.7/site-packages/watchdog/observers/api.py", line 396, in on_thread_stop
01:55:22 [INFO]      [exec]     self.unschedule_all()
01:55:22 [INFO]      [exec]   File "/usr/local/lib/python2.7/site-packages/watchdog/observers/api.py", line 392, in unschedule_all
01:55:22 [INFO]      [exec]     self._clear_emitters()
01:55:22 [INFO]      [exec]   File "/usr/local/lib/python2.7/site-packages/watchdog/observers/api.py", line 268, in _clear_emitters
01:55:22 [INFO]      [exec]     for emitter in self._emitters:
01:55:22 [INFO]      [exec] KeyError: <ObservedWatch: path=/var/folders/z2/0qcpf6l97tv6_pz56r7h67gm0000zd/T/tmpXYkMNd-nxdrive-tests-user-1/Nuxeo Drive, is_recursive=True>
01:55:22 [INFO]      [exec] -------------------- >> begin captured logging << --------------------

00:10:04 [INFO]      [exec] ======================================================================
00:10:04 [INFO]      [exec] ERROR: test_local_delete_top_level_folder (nxdrive.tests.test_integration_local_move_and_rename.TestIntegrationLocalMoveAndRename)
00:10:04 [INFO]      [exec] ----------------------------------------------------------------------
00:10:04 [INFO]      [exec] Traceback (most recent call last):
00:10:04 [INFO]      [exec]   File "/home/hudson/tmp/workspace/FT-nuxeo-drive-master-linux/nuxeo-drive-client/nxdrive/tests/common.py", line 163, in tearDown
00:10:04 [INFO]      [exec]     observer.stop()
00:10:04 [INFO]      [exec]   File "/home/hudson/.local/lib/python2.7/site-packages/watchdog/utils/__init__.py", line 113, in stop
00:10:04 [INFO]      [exec]     self.on_thread_stop()
00:10:04 [INFO]      [exec]   File "/home/hudson/.local/lib/python2.7/site-packages/watchdog/observers/api.py", line 396, in on_thread_stop
00:10:04 [INFO]      [exec]     self.unschedule_all()
00:10:04 [INFO]      [exec]   File "/home/hudson/.local/lib/python2.7/site-packages/watchdog/observers/api.py", line 392, in unschedule_all
00:10:04 [INFO]      [exec]     self._clear_emitters()
00:10:04 [INFO]      [exec]   File "/home/hudson/.local/lib/python2.7/site-packages/watchdog/observers/api.py", line 269, in _clear_emitters
00:10:04 [INFO]      [exec]     emitter.stop()
00:10:04 [INFO]      [exec]   File "/home/hudson/.local/lib/python2.7/site-packages/watchdog/utils/__init__.py", line 113, in stop
00:10:04 [INFO]      [exec]     self.on_thread_stop()
00:10:04 [INFO]      [exec]   File "/home/hudson/.local/lib/python2.7/site-packages/watchdog/observers/inotify.py", line 127, in on_thread_stop
00:10:04 [INFO]      [exec]     self._inotify.close()
00:10:04 [INFO]      [exec]   File "/home/hudson/.local/lib/python2.7/site-packages/watchdog/observers/inotify_buffer.py", line 97, in close
00:10:04 [INFO]      [exec]     self._inotify.close()
00:10:04 [INFO]      [exec]   File "/home/hudson/.local/lib/python2.7/site-packages/watchdog/observers/inotify_c.py", line 249, in close
00:10:04 [INFO]      [exec]     wd = self._wd_for_path[self._path]
00:10:04 [INFO]      [exec] KeyError: '/tmp/tmp2SbtwK-nxdrive-tests-user-1/Nuxeo Drive'
00:10:04 [INFO]      [exec] -------------------- >> begin captured logging << --------------------