python-flask `ValueError: source code string cannot contain null bytes`

Description

I'm getting error when trying to run python -m swagger_server

(venv) bu@debian:~/repos/api/out$ python -m swagger_server
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/runpy.py", line 187, in _run_module_as_main
    mod_name, mod_spec, code = _get_module_details(mod_name, _Error)
  File "/usr/local/lib/python3.10/runpy.py", line 146, in _get_module_details
    return _get_module_details(pkg_main_name, error)
  File "/usr/local/lib/python3.10/runpy.py", line 110, in _get_module_details
    __import__(pkg_name)
ValueError: source code string cannot contain null bytes

when using online generator Im not getting this issue

Swagger-codegen version

2.4.32

Swagger declaration file content or url

https://raw.githubusercontent.com/gotify/server/v2.3.0/docs/spec.json

Command line used for generation

docker run --rm -v ${PWD}:/local swaggerapi/swagger-codegen-cli generate -i /local/gotify-swagger.yaml -l python-flask -o /local/out

Steps to reproduce

Related issues/PRs

Suggest a fix/enhancement

Start with the python-flask generator command and the generated out/swagger_server package, using the linked Gotify spec.json as input. Inspect the generated Python files for the reported null-byte failure, then run python -m swagger_server to reproduce it. Done means the same generation and module-start workflow no longer raises this error.