Repository: fastapi
Issue: Pydantic v2, dataclasses, UUID, and `__annotations__`
Labels: bug

### Privileged issue

- [X] I'm @tiangolo or he asked me directly to create an issue here.

### Issue Content

The combination of using:

* Pydantic v2
* dataclasses (instead of Pydantic models)
* UUIDs
* `from future import __annotations__`

seems to break in a strange way.

This was original reported in this discussion by @sanzoghenzo: https://github.com/tiangolo/fastapi/discussions/9709#discussioncomment-6449458

In particular the comment by @raddevon with the minimal example by @fantix:

```Python
from __future__ import annotations

import uuid
from dataclasses import dataclass, field
from typing import List, Union

from fastapi import FastAPI


@dataclass
class Item:
    id: uuid.UUID
    name: str
    price: float
    tags: List[str] = field(default_factory=list)
    description: Union[str, None] = None
    tax: Union[float, None] = None


app = FastAPI()


@app.get("/items/next", response_model=Item)
async def read_next_item():
    return {
        "name": "Island In The Moon",
        "price": 12.99,
        "description": "A place to be be playin' and havin' fun",
        "tags": ["breater"],
    }
```

Starting FastAPI with that breaks with an error of:

<details>
<summary>log</summary>

```
uvicorn main:app
Traceback (most recent call last):
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/type_adapter.py", line 165, in __init__
    core_schema = _getattr_no_parents(type, '__pydantic_core_schema__')
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/type_adapter.py", line 97, in _getattr_no_parents
    raise AttributeError(attribute)
AttributeError: __pydantic_core_schema__

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 625, in _resolve_forward_ref
    obj = _typing_extra.evaluate_fwd_ref(obj, globalns=self._types_namespace)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_typing_extra.py", line 423, in evaluate_fwd_ref
    return ref._evaluate(globalns=globalns, localns=localns, recursive_guard=frozenset())
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/typing.py", line 694, in _evaluate
    eval(self.__forward_code__, globalns, localns),
  File "<string>", line 1, in <module>
NameError: name 'uuid' is not defined

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/user/code/fastapi/env3.10/bin/uvicorn", line 8, in <module>
    sys.exit(main())
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/click/core.py", line 1130, in __call__
    return self.main(*args, **kwargs)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/click/core.py", line 1055, in main
    rv = self.invoke(ctx)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/click/core.py", line 1404, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/click/core.py", line 760, in invoke
    return __callback(*args, **kwargs)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/uvicorn/main.py", line 410, in main
    run(
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/uvicorn/main.py", line 578, in run
    server.run()
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/uvicorn/server.py", line 61, in run
    return asyncio.run(self.serve(sockets=sockets))
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "uvloop/loop.pyx", line 1517, in uvloop.loop.Loop.run_until_complete
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/uvicorn/server.py", line 68, in serve
    config.load()
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/uvicorn/config.py", line 473, in load
    self.loaded_app = import_from_string(self.app)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/uvicorn/importer.py", line 21, in import_from_string
    module = importlib.import_module(module_str)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/Users/user/code/fastapi/main.py", line 24, in <module>
    async def read_next_item():
  File "/Users/user/code/fastapi/fastapi/routing.py", line 706, in decorator
    self.add_api_route(
  File "/Users/user/code/fastapi/fastapi/routing.py", line 645, in add_api_route
    route = route_class(
  File "/Users/user/code/fastapi/fastapi/routing.py", line 448, in __init__
    self.response_field = create_response_field(
  File "/Users/user/code/fastapi/fastapi/utils.py", line 99, in create_response_field
    return ModelField(**kwargs)  # type: ignore[arg-type]
  File "<string>", line 6, in __init__
  File "/Users/user/code/fastapi/fastapi/_compat.py", line 101, in __post_init__
    self._type_adapter: TypeAdapter[Any] = TypeAdapter(
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/type_adapter.py", line 167, in __init__
    core_schema = _get_schema(type, config_wrapper, parent_depth=_parent_depth + 1)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/type_adapter.py", line 80, in _get_schema
    schema = gen.generate_schema(type_)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 425, in generate_schema
    return self._annotated_schema(obj)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1464, in _annotated_schema
    schema = self._apply_annotations(source_type, annotations)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1586, in _apply_annotations
    schema = get_inner_schema(source_type)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_schema_generation_shared.py", line 82, in __call__
    schema = self._handler(__source_type)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1679, in new_handler
    schema = metadata_get_schema(source, get_inner_schema)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1675, in <lambda>
    lambda source, handler: handler(source)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_schema_generation_shared.py", line 82, in __call__
    schema = self._handler(__source_type)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1550, in inner_handler
    schema = self._generate_schema(obj)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 689, in _generate_schema
    return self.match_type(obj)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 763, in match_type
    return self._dataclass_schema(obj, None)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1317, in _dataclass_schema
    args = sorted(
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1318, in <genexpr>
    (self._generate_dc_field_schema(k, v, decorators) for k, v in fields.items()),
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 865, in _generate_dc_field_schema
    common_field = self._common_field_schema(name, field_info, decorators)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 900, in _common_field_schema
    schema = self._apply_annotations(
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1586, in _apply_annotations
    schema = get_inner_schema(source_type)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_schema_generation_shared.py", line 82, in __call__
    schema = self._handler(__source_type)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 1550, in inner_handler
    schema = self._generate_schema(obj)
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 679, in _generate_schema
    return self.generate_schema(self._resolve_forward_ref(obj))
  File "/Users/user/code/fastapi/env3.10/lib/python3.10/site-packages/pydantic/_internal/_generate_schema.py", line 627, in _resolve_forward_ref
    raise PydanticUndefinedAnnotation.from_name_error(e) from e
pydantic.errors.PydanticUndefinedAnnotation: name 'uuid' is not defined

For further information visit https://errors.pydantic.dev/2.1.1/u/undefined-annotation
```

</summary>

I still don't know if it's about which of these multiple interacting parts, I'm creating this issue to keep track of it.