Mypy plugin AssertionError with mypy 0.930

[paul-sud]

Checks

• I added a descriptive title to this issue
• I have searched (google, github) for similar issues and couldn't find anything
• I have read and followed the docs and still think this is a bug

Bug

When using the latest alpha release with mypy==0.930 I get the following error:

https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 0.930
Traceback (most recent call last):
  File "mypy/semanal.py", line 5132, in accept
  File "mypy/nodes.py", line 1005, in accept
  File "mypy/semanal.py", line 1105, in visit_class_def
  File "mypy/semanal.py", line 1184, in analyze_class
  File "mypy/semanal.py", line 1193, in analyze_class_body_common
  File "mypy/semanal.py", line 1253, in apply_class_plugin_hooks
  File "pydantic/mypy.py", line 114, in pydantic.mypy.PydanticPlugin._pydantic_model_class_maker_callback
  File "pydantic/mypy.py", line 200, in pydantic.mypy.PydanticModelTransformer.transform
  File "pydantic/mypy.py", line 341, in pydantic.mypy.PydanticModelTransformer.add_initializer
  File "pydantic/mypy.py", line 657, in pydantic.mypy.add_method
  File "mypy/semanal.py", line 4538, in named_type
  File "mypy/semanal.py", line 4505, in lookup_fully_qualified
AssertionError: 
/Users/paul/.cache/pre-commit/repo4nch0291/py_env-python3.9/lib/python3.9/site-packages/pydantic/env_settings.py:21: : note: use --pdb to drop into pdb

The behavior of named_type changed in python/mypy#11332 which causes the issue. Calls to named_type in the plugin should use builtins.X instead of __builtins__.X for the fullname arg.

Output of python -c "import pydantic.utils; print(pydantic.utils.version_info())":

             pydantic version: 1.9.0a2
            pydantic compiled: True
                 install path: /Users/paul/.cache/pre-commit/repo4nch0291/py_env-python3.9/lib/python3.9/site-packages/pydantic
               python version: 3.9.6 (default, Aug 18 2021, 18:03:48)  [Clang 11.0.3 (clang-1103.0.32.62)]
                     platform: macOS-10.16-x86_64-i386-64bit
     optional deps. installed: ['typing-extensions']

[PrettyWood]

Hi @paul-sud
Issue already tackled (see #3573 and more specifically 7168f4c)

[paul-sud]

Fantastic, thanks. I'll close this out then. I guess you can reopen if you want to use it to track alongside the PR