RecursionError: maximum recursion depth exceeded

[slavnycoder]

Here's a bug report using the provided template. I've filled in the details based on your description, leaving a placeholder for the schema URL.

---

Describe the bug
Since version 0.42.2 of datamodel-code-generator, I'm unable to convert the schema at https://github.com/MovieLabs/OMC/blob/OMC-V-2.6/OMC-JSON/OMC-JSON-v2.6.schema.json to any type of models (e.g., Pydantic, dataclasses). The tool throws error: RecursionError: maximum recursion depth exceeded.

To Reproduce

Example schema:

url provided

Used commandline:

$ datamodel-codegen --input test_data/OMC-JSON-v2.6.schema.json --input-file-type jsonschema --output models_gen.py --output-model-type pydantic_v2.BaseModel --use-annotated --snake-case-field --reuse-model --target-python-version 3.13

Expected behavior
The command should generate Python models (e.g., Pydantic models) from the provided schema URL, as it did in versions prior to 0.42.2.

Version:

• OS: Linux
• Python version: 3.13
• datamodel-code-generator version: 0.42.2 (and all later)

Additional context
The issue started specifically after upgrading to version 0.42.2. Downgrading to 0.42.1 or earlier resolves the problem. No error messages are shown in the output; the command simply produces no models.

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Would you like me to adjust the commandline example for a specific output format (e.g., Pydantic V2, dataclasses) or add more details to the reproduction steps?

[ilovelinux]

Hi @slavnycoder, thanks for reporting. I confirm I can replicate with v0.53.0.

Note

I also tried to increase the recursion limit up to 50_000 (default is 1_000) and then use it as a module without any success.

import sys

from pathlib import Path
from datamodel_code_generator import InputFileType, generate, GenerateConfig, DataModelType, PythonVersion

config = GenerateConfig(
    input_file_type=InputFileType.JsonSchema,
    output_model_type=DataModelType.PydanticV2BaseModel,
    use_annotated=True,
    snake_case_field=True,
    reuse_model=True,
    target_python_version=PythonVersion.PY_313,
    field_constraints=True, # needed by `use_annotated=True`
) 

sys.setrecursionlimit(50_000)
result = generate(Path("OMC/OMC-JSON/OMC-JSON-v2.6.schema.json"), config=config)