随机获取kivy中的线程异常

Question

在我的kivy应用程序启动期间，我一直在随机获取此线程异常（我会说此异常发生的可能性为1％）

 Exception in thread Thread-1:
 Traceback (most recent call last):
   File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
     self.run()
   File "/usr/lib/python2.7/threading.py", line 763, in run
     self.__target(*self.__args, **self.__kwargs)
   File "/usr/local/lib/python2.7/dist-packages/kivy/input/providers/mtdev.py", line 324, in _thread_run
     process([l_points[x] for x in _changes])
   File "/usr/local/lib/python2.7/dist-packages/kivy/input/providers/mtdev.py", line 198, in process
     touch = MTDMotionEvent(device, tid, args)
   File "/usr/local/lib/python2.7/dist-packages/kivy/input/motionevent.py", line 287, in __init__
     self.depack(args)
   File "/usr/local/lib/python2.7/dist-packages/kivy/input/providers/mtdev.py", line 50, in depack
     self.sx = args['x']
 KeyError: 'x'