Python modules in /agents/python/ clobbering application dependencies (e.g. typing_extensions)

[hamiltonkibbe]

Bug Report

• At what date and time did you most recently experience the problem?

2025-10-22 ~10AM ET

• Where did you experience the problem? E.g. Azure Web Apps, Azure Functions, Azure Container Registry, or offline use.

Azure Web Apps

• If your repo is publicly available please share its URL:

N/A

• What happened?

My FastAPI application on python 3.13 failed to start

• What did you expect or want to happen?

At startup FastAPI imports pydantic, which ultimately imports stuff from typing_extensions, and then ultimately launches a server that handles HTTP traffic.

I expected this all to succeed but it failed because there is a file named typing_extensions.py in /agents/python/ that is earlier in PYTHONPATH than the site-packages directory for the venv where the "real" typing_extensions module lives, as a result of this

• How can we reproduce it?

Run a "boilerplate" py13 fastapi app on linux webapp

The minimum viable reproduction would be something like this:

# requirements.txt
fastapi
uvicorn

# main.py
from fastapi import FastAPI
app = FastAPI()

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)

• Do you have log output? Please include between the backticks:

025-10-22T15:19:10.223535221Z  Updated PYTHONPATH to '/agents/python:/opt/startup/app_logs:/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages:/agents/python:/opt/startup/app_logs:/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages'
2025-10-22T15:19:14.020228603Z  Traceback (most recent call last):
2025-10-22T15:19:14.022949159Z    File "/tmp/8de117c79a5d4aa/main.py", line 3, in <module>
2025-10-22T15:19:14.022967539Z      from fastapi import FastAPI
2025-10-22T15:19:14.022986910Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/__init__.py", line 7, in <module>
2025-10-22T15:19:14.022990217Z      from .applications import FastAPI as FastAPI
2025-10-22T15:19:14.023010105Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/applications.py", line 16, in <module>
2025-10-22T15:19:14.023012742Z      from fastapi import routing
2025-10-22T15:19:14.023014951Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/routing.py", line 27, in <module>
2025-10-22T15:19:14.023017389Z      from fastapi import params, temp_pydantic_v1_params
2025-10-22T15:19:14.023019534Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/params.py", line 5, in <module>
2025-10-22T15:19:14.023021903Z      from fastapi.openapi.models import Example
2025-10-22T15:19:14.023024194Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/openapi/models.py", line 4, in <module>
2025-10-22T15:19:14.023026653Z      from fastapi._compat import (
2025-10-22T15:19:14.023028773Z      ...<6 lines>...
2025-10-22T15:19:14.023031008Z      )
2025-10-22T15:19:14.023033117Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/_compat/__init__.py", line 1, in <module>
2025-10-22T15:19:14.023035976Z      from .main import BaseConfig as BaseConfig
2025-10-22T15:19:14.023038109Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/_compat/main.py", line 12, in <module>
2025-10-22T15:19:14.023040490Z      from fastapi._compat import may_v1
2025-10-22T15:19:14.023042746Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/_compat/may_v1.py", line 4, in <module>
2025-10-22T15:19:14.023045220Z      from fastapi.types import ModelNameMap
2025-10-22T15:19:14.023047363Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/fastapi/types.py", line 5, in <module>
2025-10-22T15:19:14.023049743Z      from pydantic import BaseModel
2025-10-22T15:19:14.023051864Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/pydantic/__init__.py", line 5, in <module>
2025-10-22T15:19:14.023054231Z      from ._migration import getattr_migration
2025-10-22T15:19:14.023056349Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/pydantic/_migration.py", line 4, in <module>
2025-10-22T15:19:14.023523184Z      from pydantic.warnings import PydanticDeprecatedSince20
2025-10-22T15:19:14.023528463Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/pydantic/warnings.py", line 5, in <module>
2025-10-22T15:19:14.023531244Z      from .version import version_short
2025-10-22T15:19:14.023534598Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/pydantic/version.py", line 7, in <module>
2025-10-22T15:19:14.023543275Z      from pydantic_core import __version__ as __pydantic_core_version__
2025-10-22T15:19:14.023545807Z    File "/tmp/8de117c79a5d4aa/antenv/lib/python3.13/site-packages/pydantic_core/__init__.py", line 6, in <module>
2025-10-22T15:19:14.023548322Z      from typing_extensions import Sentinel
2025-10-22T15:19:14.023550539Z  ImportError: cannot import name 'Sentinel' from 'typing_extensions' (/agents/python/typing_extensions.py)

Ideally /agents/python/ would be later in PYTHONPATH, or would not contain python modules that clobber popular packages.

[aboondooley]

We also ran into this issue during our deployment last night ☹️
If anyone needs a work around before this is fixed, this is what worked for us:

As mentioned above, the issue is that /agents/python/ is listed earlier in the PYTHONPATH, so we just removed agents/python from the PYTHONPATH by adding this to our startup.sh script:

echo "Current PYTHONPATH: $PYTHONPATH"

# Remove /agents/python from the PYTHONPATH
export PYTHONPATH=$(echo "$PYTHONPATH" | sed 's|/agents/python:||g')

echo "Modified PYTHONPATH: $PYTHONPATH"