KeyError: '__main__.Model1:95063711754448'

[jherbel]

Initial Checks

• I confirm that I'm using Pydantic V2

Description

The code below crashes with the following traceback. See also #8897, which was closed.

Traceback (most recent call last):
  File "/home/joerg/tmp/pydantic_key_error.py", line 22, in <module>
    class Model4(BaseModel, frozen=True):
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_model_construction.py", line 202, in __new__
    complete_model_class(
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_model_construction.py", line 549, in complete_model_class
    schema = gen_schema.clean_schema(schema)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 435, in clean_schema
    schema = simplify_schema_references(schema)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 463, in simplify_schema_references
    schema = walk_core_schema(schema, count_refs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 414, in walk_core_schema
    return f(schema.copy(), _dispatch)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 459, in count_refs
    recurse(definitions[ref], count_refs)
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 197, in walk
    return f(schema, self._walk)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 447, in count_refs
    return recurse(s, count_refs)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 200, in _walk
    schema = self._schema_type_to_method[schema['type']](schema.copy(), f)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 209, in _handle_other_schemas
    schema['schema'] = self.walk(sub_schema, f)  # type: ignore
                       ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 197, in walk
    return f(schema, self._walk)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 447, in count_refs
    return recurse(s, count_refs)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 200, in _walk
    schema = self._schema_type_to_method[schema['type']](schema.copy(), f)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 337, in handle_model_fields_schema
    replaced_field['schema'] = self.walk(v['schema'], f)
                               ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 197, in walk
    return f(schema, self._walk)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 459, in count_refs
    recurse(definitions[ref], count_refs)
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 200, in _walk
    schema = self._schema_type_to_method[schema['type']](schema.copy(), f)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 209, in _handle_other_schemas
    schema['schema'] = self.walk(sub_schema, f)  # type: ignore
                       ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 197, in walk
    return f(schema, self._walk)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 447, in count_refs
    return recurse(s, count_refs)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 200, in _walk
    schema = self._schema_type_to_method[schema['type']](schema.copy(), f)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 337, in handle_model_fields_schema
    replaced_field['schema'] = self.walk(v['schema'], f)
                               ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 197, in walk
    return f(schema, self._walk)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 447, in count_refs
    return recurse(s, count_refs)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 203, in _walk
    schema['serialization'] = self._handle_ser_schemas(ser_schema, f)
                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 215, in _handle_ser_schemas
    ser_schema['schema'] = self.walk(schema, f)  # type: ignore
                           ^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 197, in walk
    return f(schema, self._walk)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic/_internal/_core_utils.py", line 459, in count_refs
    recurse(definitions[ref], count_refs)
            ~~~~~~~~~~~^^^^^
KeyError: '__main__.Model1:110296424761552'

Example Code

from collections.abc import Sequence
from pydantic import PlainValidator, BaseModel
from typing import Annotated


class Model1(BaseModel, frozen=True):
    ...


def parse_model1(x: object) -> Model1:
    return Model1()


class Model2(BaseModel, frozen=True):
    model1:  Annotated[Model1, PlainValidator(parse_model1)]


class Model3(BaseModel, frozen=True):
    model2: Sequence[Model2]


class Model4(BaseModel, frozen=True):
    model2: Model2

Python, Pydantic & OS Version

pydantic version: 2.7.0
pydantic-core version: 2.18.1
pydantic-core build: profile=release pgo=true
install path: /home/joerg/.pyenv/versions/3.12.1/lib/python3.12/site-packages/pydantic
python version: 3.12.1 (main, Jan  9 2024, 15:28:21) [GCC 11.4.0]
platform: Linux-6.5.0-28-generic-x86_64-with-glibc2.35
related packages: typing_extensions-4.9.0
commit: unknown

[sydney-runkle]

Hmph, definitely a bug. Thanks for the report. Will attempt to fix for 2.7.2