KeyError: 'DISPLAY' in stop

[ryancc9]

Hi,
Thanks for the awesome wrapper!
I'm getting the below error running dryscrape with xvfbwrapper.
Ubuntu 16.04.2 LTS (Ubuntu Mate)
Python 2.7.12
xvfbwrapper-0.2.9

Error in sys.exitfunc:
Traceback (most recent call last):
File "/usr/lib/python2.7/atexit.py", line 24, in _run_exitfuncs
func(*targs, **kargs)
File "/usr/local/lib/python2.7/dist-packages/xvfbwrapper.py", line 84, in stop
del os.environ['DISPLAY']
File "/usr/lib/python2.7/os.py", line 498, in delitem
del self.data[key]
KeyError: 'DISPLAY'

I'm not sure this is the best solution, but I was able to fix this by adding "if 'DISPLAY' in os.environ:" to check that 'DISPLAY' actually exists.

            if self.orig_display is None:
                if 'DISPLAY' in os.environ:
                   del os.environ['DISPLAY']

[gariel]

I have the same problem, to temporary fix I added the DISPLAY key on os.environ dict before start:

    def start(self):
        # fixing an exception raised in xvfb
        os.environ['DISPLAY'] = ':0'

        self._xvfb.start()

Python 3.7.3
xvfbwrapper-0.2.9