from __future__ import annotations causes __pydantic_extra__ type annotation error.

[KasperZutterman]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

Importing from __future__ import annotations breaks model definition if it contains __pydantic_extra__ type annotation.

Exception stack trace

Traceback (most recent call last):
  File "/Users/kasperzutterman/repositories/otainsight/transformations/modules/integrations/transformations/pms/tests/hotelkey/test3.py", line 6, in <module>
    class Test(BaseModel):
  File "/Users/kasperzutterman/.pyenv/versions/3.10.12/envs/pydantic/lib/python3.10/site-packages/pydantic/_internal/_model_construction.py", line 183, in __new__
    complete_model_class(
  File "/Users/kasperzutterman/.pyenv/versions/3.10.12/envs/pydantic/lib/python3.10/site-packages/pydantic/_internal/_model_construction.py", line 517, in complete_model_class
    schema = cls.__get_pydantic_core_schema__(cls, handler)
  File "/Users/kasperzutterman/.pyenv/versions/3.10.12/envs/pydantic/lib/python3.10/site-packages/pydantic/main.py", line 584, in __get_pydantic_core_schema__
    return __handler(__source)
  File "/Users/kasperzutterman/.pyenv/versions/3.10.12/envs/pydantic/lib/python3.10/site-packages/pydantic/_internal/_schema_generation_shared.py", line 82, in __call__
    schema = self._handler(__source_type)
  File "/Users/kasperzutterman/.pyenv/versions/3.10.12/envs/pydantic/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 499, in generate_schema
    schema = self._generate_schema(obj)
  File "/Users/kasperzutterman/.pyenv/versions/3.10.12/envs/pydantic/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 737, in _generate_schema
    schema = self._post_process_generated_schema(self._generate_schema_inner(obj))
  File "/Users/kasperzutterman/.pyenv/versions/3.10.12/envs/pydantic/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 759, in _generate_schema_inner
    return self._model_schema(obj)
  File "/Users/kasperzutterman/.pyenv/versions/3.10.12/envs/pydantic/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 543, in _model_schema
    raise PydanticSchemaGenerationError(
pydantic.errors.PydanticSchemaGenerationError: The type annotation for `__pydantic_extra__` must be `Dict[str, ...]`

Example Code

from __future__ import annotations  # <- removing this line solves the problem

from pydantic import BaseModel, ConfigDict


class Test(BaseModel):
    model_config = ConfigDict(extra='allow')
    __pydantic_extra__: dict[str, str]

Python, Pydantic & OS Version

pydantic version: 2.6.1
        pydantic-core version: 2.16.2
          pydantic-core build: profile=release pgo=true
                 install path: /Users/kasperzutterman/.pyenv/versions/3.12.1/envs/pydantic-3.12/lib/python3.12/site-packages/pydantic
               python version: 3.12.1 (main, Feb  2 2024, 09:13:09) [Clang 15.0.0 (clang-1500.1.0.2.5)]
                     platform: macOS-14.2.1-arm64-arm-64bit
             related packages: typing_extensions-4.9.0
                       commit: unknown

[sydney-runkle]

@KasperZutterman,

This should be fixed on main, thanks to @alexmojaki's work in #8659.