I am unable to connect to Fennec with Marionette enabled (built with ENABLE_MARIONETTE=1). The python client gives: Traceback (most recent call last): File "run-benchmark.py", line 4, in <module> marionette.start_session() File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/marionette_driver-0.10-py2.7.egg/marionette_driver/marionette.py", line 1015, in start_session self.session = self._send_message('newSession', 'value', capabilities=desired_capabilities, sessionId=session_id) File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/marionette_driver-0.10-py2.7.egg/marionette_driver/decorators.py", line 36, in _ return func(*args, **kwargs) File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/marionette_driver-0.10-py2.7.egg/marionette_driver/marionette.py", line 691, in _send_message response = self.client.send(message) File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/marionette_transport-0.5-py2.7.egg/marionette_transport/transport.py", line 101, in send self.connect() File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/marionette_transport-0.5-py2.7.egg/marionette_transport/transport.py", line 95, in connect self.actor = response['id'] KeyError: 'id'

Unfortunately it's busted because it's not implemented :) Sorry.