any reason why ExtendedTraverserVisitor does not set allow_interpreted_subclasses=True?

[akcheung]

Feature

I got a TypeError: interpreted classes cannot inherit from compiled when I tried to extend from it. Not sure if this is a bug or not.

To reproduce:

from mypy.parse import parse
from mypy.traverser import ExtendedTraverserVisitor

class FooVisitor(ExtendedTraverserVisitor):
    def visit(self, o: Node) -> bool:
        print("hello")
        return True

parse("print('foo')", None, None, None, Options()).accept(FooVisitor())

[flying-sheep]

Oh no, that makes my proposed plugin also pretty much impossible. (I want to subclass stubgen.ASTStubGenerator)

Is there any workaround that doesn’t involve copying hundreds of lines of code like the workaround in dosisod/refurb#309?