Older python-six from early RHEL and ubuntu do not have add_metaclass but do have with_metaclass

lib/ansible/plugins/cache/base.py

@@ -20,11 +20,10 @@ __metaclass__ = type
 
 from abc import ABCMeta, abstractmethod
 
-from six import add_metaclass
+from six import with_metaclass
 
 
-@add_metaclass(ABCMeta)
+class BaseCacheModule(with_metaclass(ABCMeta, object)):
-class BaseCacheModule:
 
     @abstractmethod
     def get(self, key):

lib/ansible/plugins/connections/__init__.py

@@ -22,7 +22,7 @@ __metaclass__ = type
 
 from abc import ABCMeta, abstractmethod, abstractproperty
 
-from six import add_metaclass
+from six import with_metaclass
 
 from ansible import constants as C
 from ansible.errors import AnsibleError
@@ -34,8 +34,7 @@ from ansible.utils.display import Display
 
 __all__ = ['ConnectionBase']
 
-@add_metaclass(ABCMeta)
+class ConnectionBase(with_metaclass(ABCMeta, object)):
-class ConnectionBase:
     '''
     A base class for connections to contain common code.
     '''

lib/ansible/plugins/inventory/__init__.py

@@ -23,10 +23,9 @@ __metaclass__ = type
 
 from abc import ABCMeta, abstractmethod
 
-from six import add_metaclass
+from six import with_metaclass
 
-@add_metaclass(ABCMeta)
+class InventoryParser(with_metaclass(ABCMeta, object)):
-class InventoryParser:
     '''Abstract Base Class for retrieving inventory information
 
     Any InventoryParser functions by taking an inven_source.  The caller then