Traceback (most recent call last):

 "/home/damien/test-venv/bin/py.test", line 8, in <module>
load_entry_point('pytest==2.4.0', 'console_scripts', 'py.test')()

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/config.py", line 18, in main
config = _prepareconfig(args, plugins)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/config.py", line 63, in _prepareconfig
pluginmanager=pluginmanager, args=args)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/core.py", line 364, in __call__
return self._docall(methods, kwargs)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/core.py", line 375, in _docall
res = mc.execute()

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/core.py", line 293, in execute
res = method(**kwargs)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/helpconfig.py", line 25, in pytest_cmdline_parse
config = __multicall__.execute()

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/core.py", line 293, in execute
res = method(**kwargs)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/config.py", line 618, in pytest_cmdline_parse
self.parse(args)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/config.py", line 711, in parse
self._preparse(args)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/config.py", line 691, in _preparse
args=args, parser=self._parser)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/core.py", line 364, in __call__
return self._docall(methods, kwargs)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/core.py", line 375, in _docall
res = mc.execute()

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/core.py", line 293, in execute
res = method(**kwargs)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/capture.py", line 17, in pytest_load_initial_conftests
ns = parser.parse_known_args(args)

 "/home/damien/test-venv/lib/python2.6/site-packages/_pytest/config.py", line 175, in parse_known_args
return optparser.parse_known_args(args)[0]AttributeError: 'MyOptionParser' object has no attribute 'parse_known_args'
Traceback (most recent call last):

 "/usr/lib/python3/dist-packages/nose/failure.py", line 39, in runTest
raise self.exc_val.with_traceback(self.tb)

 "/usr/lib/python3/dist-packages/nose/loader.py", line 400, in loadTestsFromName
module = resolve_name(addr.module)

 "/usr/lib/python3/dist-packages/nose/util.py", line 311, in resolve_name
module = **import**('.'.join(parts_copy))

 "/usr/lib/python3/dist-packages/matplotlib/tests/**init**.py", line 17, in <module>
'The baseline image directory does not exist. 'OSError: The baseline image directory does not exist. This is most likely because the test data is not installed. You may need to install matplotlib from source to get the test data.