NodeMixin - TypeError: multiple bases have instance lay-out conflict

Works: 2.4.3 Breaks: 2.6.0

>>> from munch import Munch
>>> from anytree import NodeMixin
>>> class MyClass(Munch, NodeMixin):
...     pass
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: multiple bases have instance lay-out conflict

Where munch is https://github.com/Infinidat/munch

Googling around a bit this seems to be about conflicts in C implementations of classes on __foo__ attributes. So I did this:

>>> [k for k in dir(Munch) if k in dir(NodeMixin)]
['__class__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__']

but it didn’t make me feel much smarter.

Does this mean anything to you anytree peeps? I came here because obviously NodeMixin is meant to be mixed in so this feels like a bug rather than just a stupid thing I should not be attempting to do. Especially as it used to work until this version.

[c0fec0de]

slots will be removed

[c0fec0de]

Yes. __slots__ has been added. Please try:

>>> from munch import Munch
>>> from anytree import NodeMixin
>>> class MyNodeMixin(NodeMixin):
...     pass
>>> class MyClass(Munch, MyNodeMixin):
...     pass

As __slots__ is not inherited, it might work