Merge 7d6599b027 into 1d434dec47

fastapi/_compat.py

@@ -56,6 +56,9 @@ if PYDANTIC_V2:
     )
     from pydantic._internal._typing_extra import eval_type_lenient
     from pydantic._internal._utils import lenient_issubclass as lenient_issubclass
+    from pydantic.errors import (
+        PydanticUndefinedAnnotation as PydanticUndefinedAnnotation,
+    )
     from pydantic.fields import FieldInfo
     from pydantic.json_schema import GenerateJsonSchema as GenerateJsonSchema
     from pydantic.json_schema import JsonSchemaValue as JsonSchemaValue
@@ -367,6 +370,9 @@ else:
     class PydanticSchemaGenerationError(Exception):  # type: ignore[no-redef]
         pass
 
+    class PydanticUndefinedAnnotation(Exception):  # type: ignore[no-redef]
+        pass
+
     def with_info_plain_validator_function(  # type: ignore[misc]
         function: Callable[..., Any],
         *,

fastapi/utils.py

@@ -20,6 +20,7 @@ from fastapi._compat import (
     BaseConfig,
     ModelField,
     PydanticSchemaGenerationError,
+    PydanticUndefinedAnnotation,
     Undefined,
     UndefinedType,
     Validator,
@@ -94,7 +95,7 @@ def create_model_field(
         )
     try:
         return ModelField(**kwargs)  # type: ignore[arg-type]
-    except (RuntimeError, PydanticSchemaGenerationError):
+    except (RuntimeError, PydanticSchemaGenerationError, PydanticUndefinedAnnotation):
         raise fastapi.exceptions.FastAPIError(
             "Invalid args for response field! Hint: "
             f"check that {type_} is a valid Pydantic field type. "