You need to run the program with the following:

  python -X dev -c "from gunicorn.app.wsgiapp import run; run()" --workers=1 foobar:app

where foobar.py is the code from the previous message.

The crash happen when, the function `app` is executed, hence you need to call in another console:

curl http://localhost:8000

note: lsm package can be installed with pip install lsm-db
note2: lsm db can not be installed with py3.9