[jborean93]

You should continue to use the setup.py to define the extensions but put all the remaining metadata in the pyproject.toml. The pyproject.toml will reference setuptools as your build backend like https://github.com/jborean93/pyspnego/blob/main/pyproject.to... and the setup.py will reference anything that cannot be expressed in the pyproject.toml like C extensions https://github.com/jborean93/pyspnego/blob/main/setup.py.

The benefits of this is now your project has metadata that tools like pip/poetry/etc can use to figure out what is required (Python project wise) to build your project. For example pip will create an isolated venv with setuptools and Cython for the project I listed when installing from the sdist. You can now also take advantage of `python -m build` to build this project rather than a setuptools specific incantation. This is universal across all build providers so if you want to change to poetry in the future you can will hopefully no build script changes.

[eesmith]

I know my project is an oddball. So far I have no required external dependencies, and my optional dependencies are for what the linked-to pages refer to as "native dependencies", which can't be specified by pyproject.toml.

My "setuptools specific incantation" is "pip install" or "pip install -e". I do have a setup.cfg.

The recommendation last year was "If you're building an application, use Poetry. If you're building a library, use Flit", and since my package is a library, I've never really considered poetry.

But! I'm switching from argparse to click - my first required dependency! - so within a month or so I'll be putting my toes into the pyproject.toml waters.

Thank you for your pointers. Isn't there also a way to specify the requirements for building the documentation? I didn't see it in your example.