having just converted a large project/monorepo to poetry, its pretty easy to generate setup.py/requirements from pyproject.toml https://github.com/cloud-custodian/cloud-custodian/blob/mast...

note most of this just working around poetry for multiple packages in a single repo, with interdependencies. flip side, our pip/setuptools users building trunk from ci are unaffected.

that said there are open questions on poetry (governance/dev community), but the experience is overall pretty solid with a some minor rough edges, and the fact that it has a usable api makes those pretty minor. in contrast the only api on pip is cli arguments for subprocess/fork.