# Buggy code
def __init__(self, *args, **kwargs):
    self.plugin_name = self.__module__.split(".")[-1]
    self._timeout = float(C.CACHE_PLUGIN_TIMEOUT)
    self._cache = {}
    self._cache_dir = None

    if C.CACHE_PLUGIN_CONNECTION:
        # expects a dir path
        self._cache_dir = os.path.expanduser(
            os.path.expandvars(C.CACHE_PLUGIN_CONNECTION)
        )

    if not self._cache_dir:
        raise AnsibleError(
            "error, '%s' cache plugin requires the 'fact_caching_connection' config option"
            " to be set (to a writeable directory path)" % self.plugin_name
        )

    if not os.path.exists(self._cache_dir):
        try:
            os.makedirs(self._cache_dir)
        except (OSError, IOError) as e:
            display.warning(
                "error in '%s' cache plugin while trying to create cache dir %s : %s"
                % (self.plugin_name, self._cache_dir, to_bytes(e))
            )
            return None


# Traceback (UnboundLocalError)
fatal: [my-host] => Traceback (most recent call last):
File "/home/david/.pip/ansible/lib/ansible/runner/__init__.py", line 586, in _executor
exec_rc = self._executor_internal(host, new_stdin)
File "/home/david/.pip/ansible/lib/ansible/runner/__init__.py", line 668, in _executor_internal
inject = self.get_inject_vars(host)
File "/home/david/.pip/ansible/lib/ansible/runner/__init__.py", line 611, in get_inject_vars
combined_cache = self.get_combined_cache()
File "/home/david/.pip/ansible/lib/ansible/runner/__init__.py", line 606, in get_combined_cache
combined_cache = self.setup_cache.copy()
File "/home/david/.pip/ansible/lib/ansible/cache/__init__.py", line 54, in copy
return dict([(k, v) for (k, v) in self.iteritems()])
File "/usr/lib/python2.7/_abcoll.py", line 406, in iteritems
yield (key, self[key])
File "/home/david/.pip/ansible/lib/ansible/cache/__init__.py", line 35, in __getitem__
return self._plugin.get(key)
File "/home/david/.pip/ansible/lib/ansible/cache/jsonfile.py", line 69, in get
f.close()
UnboundLocalError: local variable 'f' referenced before assignment

# Fixed code
def __init__(self, *args, **kwargs):
    self.plugin_name = self.__module__.split(".")[-1]
    self._timeout = float(C.CACHE_PLUGIN_TIMEOUT)
    self._cache = {}
    self._cache_dir = None

    if C.CACHE_PLUGIN_CONNECTION:
        # expects a dir path
        self._cache_dir = os.path.expanduser(
            os.path.expandvars(C.CACHE_PLUGIN_CONNECTION)
        )

    if not self._cache_dir:
        raise AnsibleError(
            "error, '%s' cache plugin requires the 'fact_caching_connection' config option"
            " to be set (to a writeable directory path)" % self.plugin_name
        )

    if not os.path.exists(self._cache_dir):
        try:
            os.makedirs(self._cache_dir)
        except (OSError, IOError) as e:
            raise AnsibleError(
                "error in '%s' cache plugin while trying to create cache dir %s : %s"
                % (self.plugin_name, self._cache_dir, to_bytes(e))
            )
    else:
        for x in (os.R_OK, os.W_OK, os.X_OK):
            if not os.access(self._cache_dir, x):
                raise AnsibleError(
                    "error in '%s' cache, configured path (%s) does not have necessary permissions (rwx), disabling plugin"
                    % (self.plugin_name, self._cache_dir)
                )