It seems like pipenv and poetry fill different niches: pipenv is intended for application deployment, so you're likely to only have one version of python, while

It seems like pipenv and poetry fill different niches: pipenv is intended for application deployment, so you're likely to only have one version of python, while poetry is intended for building libraries. I found the tox support a bit hacky, but not bad, and got 3.5 to 3.8 testing just fine. Poetry does make the publishing process pretty seamless for the simple case. If you're starting a new library, poetry is great. I think poetry needs a "fuzz option" to test random valid solutions to the version constraints, to check if the older versions are really valid.