Failure of poetry on hello world?

[skramm]

Thanks for what seems to be a great resource!
I'm currently struggling though it but I am encountering a strange error on first step:
https://christophergs.com/tutorials/ultimate-fastapi-tutorial-pt-1-hello-world/

Probably some stupid python thing, but I lack the background that would help me get through it, so if you have an idea...

I cloned the repo, installed poetry, seems everything is fine, but running the following line within the part-01-hello-world folder fails:

$ poetry run ./run.sh 
/usr/lib/python3/dist-packages/requests/__init__.py:89: RequestsDependencyWarning: urllib3 (1.26.16) or chardet (3.0.4) doesn't match a supported version!
  warnings.warn("urllib3 ({}) or chardet ({}) doesn't match a supported "
Creating virtualenv app-OgzSzvj8-py3.8 in /home/sk/.cache/pypoetry/virtualenvs

module 'virtualenv.create.via_global_ref.builtin.cpython.mac_os' has no attribute 'CPython2macOsFramework'

I think the warning is not critical (or is it?) but the missing attribute seems to prevent running the app.

FWIW:

• OS: Ubuntu 20.04.6 LTS (default "python" is 2.7.18, thus I specify "python3" and "pip3" everywere)

$ python3 --version
Python 3.8.10

$ poetry --version
/usr/lib/python3/dist-packages/requests/__init__.py:89: RequestsDependencyWarning: urllib3 (1.26.16) or chardet (3.0.4) doesn't match a supported version!
  warnings.warn("urllib3 ({}) or chardet ({}) doesn't match a supported "
Poetry (version 1.5.1)

$ pip3 freeze | grep fastapi
fastapi==0.96.0

Any idea what I can check next?