Possible bug in "metaclass resolution order" ?

[Simon Percivall]

If you have read the document I referred you to, did you also read the
example where classes M1, M2, M3 and M4 were defined?

A quote from the discussion of that example:
"For class D, the explicit metaclass M1 is not a subclass of the base
metaclasses (M2, M3), but choosing M3 satisfies the constraint, so
D.__class__ is M3."

Isn't that exactly what you are doing?