We get this error when running tests with pipenv (pipenv run pytest)

python version: 2.7.12
pytest version: 3.7.0
pluggy version: 0.7.1
pathlib version: 2.1.0

INTERNALERROR> Tracebak (most recent call last):
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/_pytest/main.py", line 174, in wrap_session
INTERNALERROR> config._do_configure()
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/_pytest/config/init.py", line 588, in _do_configure
INTERNALERROR> self.hook.pytest_configure.call_historic(kwargs=dict(config=self))
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pluggy/hooks.py", line 280, in call_historic
INTERNALERROR> res = self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pluggy/manager.py", line 67, in _hookexec
INTERNALERROR> return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pluggy/manager.py", line 61, in
INTERNALERROR> firstresult=hook.spec_opts.get('firstresult'),
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pluggy/callers.py", line 201, in _multicall
INTERNALERROR> return outcome.get_result()
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pluggy/callers.py", line 77, in get_result
INTERNALERROR> _reraise(*ex) # noqa
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pluggy/callers.py", line 180, in _multicall
INTERNALERROR> res = hook_impl.function(*args)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/_pytest/cacheprovider.py", line 292, in pytest_configure
INTERNALERROR> config.cache = Cache.for_config(config)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/_pytest/cacheprovider.py", line 40, in for_config
INTERNALERROR> cachedir = cls.cache_dir_from_config(config)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/_pytest/cacheprovider.py", line 48, in cache_dir_from_config
INTERNALERROR> return paths.resolve_from_str(config.getini("cache_dir"), config.rootdir)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/_pytest/paths.py", line 7, in resolve_from_str
INTERNALERROR> root = Path(root)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pathlib2.py", line 1095, in new
INTERNALERROR> self = cls._from_parts(args, init=False)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pathlib2.py", line 760, in _from_parts
INTERNALERROR> drv, root, parts = self._parse_args(args)
INTERNALERROR> File ".venv/local/lib/python2.7/site-packages/pathlib2.py", line 752, in _parse_args
INTERNALERROR> % type(a))
INTERNALERROR> TypeError: argument should be a path or str object, not <class 'py._path.local.LocalPath'>