I get the the error "AttributeError: 'ActionGroup' object has no attribute
'add_actions'" when executing the following code with python3:

Python 3.6.4 (default, Jan 03 2018, 13:52:55) [GCC] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from gi.repository import Gtk
__main__:1: PyGIWarning: Gtk was imported without specifying a version first.
Use gi.require_version('Gtk', '3.0') before import to ensure that the right
version gets loaded.
>>> g = Gtk.ActionGroup()
>>> g.add_actions(['test'])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'ActionGroup' object has no attribute 'add_actions'

This produces problems with e.g. Gramps (
https://gramps-project.org/bugs/view.php?id=10423 ). I have an up-to-date
Tumbleweed system with python3-gobject-3.26.1-1.1.