Race condition when file is updated

[ezyang]

On OS X, when I run Jure and then edit a file in vim, I get this error:

Traceback (most recent call last):
  File "/Users/ezyang/miniconda3/lib/python3.8/threading.py", line 932, in _bootstrap_inner
    self.run()
  File "/Users/ezyang/miniconda3/lib/python3.8/site-packages/watchdog/observers/api.py", line 203, in run
    self.dispatch_events(self.event_queue, self.timeout)
  File "/Users/ezyang/miniconda3/lib/python3.8/site-packages/watchdog/observers/api.py", line 376, in dispatch_events
    handler.dispatch(event)
  File "/Users/ezyang/miniconda3/lib/python3.8/site-packages/watchdog/events.py", line 331, in dispatch
    {
  File "/Users/ezyang/miniconda3/lib/python3.8/site-packages/jure/handlers.py", line 125, in on_modified
    file_update_timestamp = get_file_update_timestamp(self.file_path)
  File "/Users/ezyang/miniconda3/lib/python3.8/site-packages/jure/utils.py", line 43, in get_file_update_timestamp
    statbuf = os.stat(file_path)
FileNotFoundError: [Errno 2] No such file or directory: '/Users/ezyang/Dev/subclass_zoo/simple_functorch.py'

seems like some sort of race condition