six 1.11.0 causes TypeError: Error when calling the metaclass bases

[florenthemmi]

Version 1.11.0 of the six package was released yesterday and causes:

  File "/Users/florenthemmi/dev/env/lib/python2.7/site-packages/apache_beam/internal/gcp/json_value.py", line 23, in <module>
    from apitools.base.py import extra_types
  File "/Users/florenthemmi/dev/env/lib/python2.7/site-packages/apitools/base/py/__init__.py", line 21, in <module>
    from apitools.base.py.base_api import *
  File "/Users/florenthemmi/dev/env/lib/python2.7/site-packages/apitools/base/py/base_api.py", line 31, in <module>
    from apitools.base.protorpclite import message_types
  File "/Users/florenthemmi/dev/env/lib/python2.7/site-packages/apitools/base/protorpclite/message_types.py", line 25, in <module>
    from apitools.base.protorpclite import messages
  File "/Users/florenthemmi/dev/env/lib/python2.7/site-packages/apitools/base/protorpclite/messages.py", line 1165, in <module>
    class Field(six.with_metaclass(_FieldMeta, object)):
TypeError: Error when calling the metaclass bases
    metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases

This issue has been encountered by several more folks and has been reported as issue benjaminp/six#210.

This issue is to track its resolution, or to make whatever change in apitools could fix this.