crash when extending `typing_extensions.Annotated`

[DetachHead]

from typing_extensions import Annotated

class A(Annotated): pass

Sandpit\Test.py:172: error: INTERNAL ERROR -- Please try using mypy master on Github:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
    analyzer.refresh_partial(refresh_node,
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\semanal.py", line 405, in refresh_partial
    self.refresh_top_level(node)
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\semanal.py", line 416, in refresh_top_level
    self.accept(d)
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\semanal.py", line 5092, in accept
    node.accept(self)
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\nodes.py", line 1000, in accept
    return visitor.visit_class_def(self)
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\semanal.py", line 1105, in visit_class_def
    self.analyze_class(defn)
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\semanal.py", line 1127, in analyze_class
    bases, tvar_defs, is_protocol = self.clean_up_bases_and_infer_type_variables(
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\semanal.py", line 1337, in clean_up_bases_and_infer_type_variables
    all_tvars = self.get_all_bases_tvars(base_type_exprs, removed)
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\semanal.py", line 1428, in get_all_bases_tvars
    base_tvars = base.accept(TypeVarLikeQuery(self.lookup_qualified, self.tvar_scope))
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\types.py", line 615, in accept
    return visitor.visit_unbound_type(self)
  File "C:\Users\user\project\.venv\lib\site-packages\mypy\typeanal.py", line 1296, in visit_unbound_type
    return self.query_types([t.args[0]])
IndexError: tuple index out of range

broken in 0.940+dev.56684e43a14e3782409c47e99bb47191d631a3de but works in 0.920

[sobolevn]

Fix is on its way! Thanks for the report! 👍