The "used directly as the metaclass" is a reference to https://docs.python.org/3/reference/datamodel.html#creating-the-class-object further down, and specifically the "metaclass(name, bases, namespace, **kwds)" call. It's not saying Python has a way to bypass that instantiation process.

As a result, your code is consistently getting to that step just fine, but *that call* is throwing an exception.

Hence my comment earlier that there's a case to be made that we should be better indicating where we were in the type creation process when the metaclass resolution failed.