Traceback (most recent call last):
  File "c:\mozilla-build\env1\Scripts\mozcommitbuilder-script.py", line 8, in <m
odule>
    load_entry_point('mozcommitbuilder==0.285', 'console_scripts', 'mozcommitbui
lder')()
  File "c:\mozilla-build\env1\lib\site-packages\mozcommitbuilder\builder.py", li
ne 248, in cli
    builder.bisect(options.good,options.bad)
  File "c:\mozilla-build\env1\lib\site-packages\mozcommitbuilder\builder.py", li
ne 120, in bisect
    self.bisectRecurse()
  File "c:\mozilla-build\env1\lib\site-packages\mozcommitbuilder\builder.py", li
ne 136, in bisectRecurse
    runner = FirefoxRunner()
  File "c:\mozilla-build\env1\lib\site-packages\mozrunner\__init__.py", line 371
, in __init__
    self.binary = self.find_binary()
  File "c:\mozilla-build\env1\lib\site-packages\mozrunner\__init__.py", line 432
, in find_binary
    path = os.path.join(*bin)
  File "c:\mozilla-build\env1\lib\ntpath.py", line 96, in join
    assert len(path) > 0
TypeError: object of type 'NoneType' has no len()
Exception AttributeError: "'FirefoxRunner' object has no attribute 'profile'" in
 <bound method FirefoxRunner.cleanup of <mozrunner.FirefoxRunner object at 0x01B
64730>> ignored