Comment 2 for bug 1918864

Traceback (most recent call last):
  File "/home/zuul/src/opendev.org/openstack/swift/test/cors/main.py", line 182, in run
    browser = driver()
  File "/usr/lib/python2.7/site-packages/selenium/webdriver/firefox/webdriver.py", line 174, in __init__
    keep_alive=True)
  File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 157, in __init__
    self.start_session(capabilities, browser_profile)
  File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 252, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 321, in execute
    self.error_handler.check_response(response)
  File "/usr/lib/python2.7/site-packages/selenium/webdriver/remote/errorhandler.py", line 242, in check_response
    raise exception_class(message, screen, stacktrace)
WebDriverException: Message: invalid argument: can't kill an exited process

Looks like I'll be digging into selenium...