At first glance, the CI failure here (https://github.com/python-poetry/poetry-core/pull/39/checks?check_run_id=814831965) seems like a Poetry bug that's unrelated to the changes here.

If I'm reading it right, seems like Poetry wants to install futures because isort requires it but the futures version doesn't support Python versions >=3.0. poetry-core however does support python ^3.5. What Poetry doesn't seem to understand is that isort (and thus poetry-core) only needs futures when python_version < "3.2", so I believe there shouldn't be a conflict.

I could perhaps simply remove isort from dev-dependencies as it seems we only run it in pre-commit anyways?

I tried to remove the isort dev-dependency, but it did not fix the failing CI, because another dependency had the same conditional futures dependency, so the same issue persisted.

I guess the root cause should be fixed then.

For the record, here's Poetry output from the failing Python 2.7 CI run:

SolverProblemError

The current project's Python requirement (~2.7 || ^3.5) is not compatible with some of the required packages Python requirement:
  - futures requires Python >=2.6, <3, so it will not be satisfied for Python >=3.5,<4.0

Because no versions of isort match >4.3.21,<5.0.0
 and isort (4.3.21) depends on futures (*), isort (>=4.3.21,<5.0.0) requires futures (*).
Because futures (3.3.0) requires Python >=2.6, <3
 and no versions of futures match !=3.3.0, futures is forbidden.
Thus, isort is forbidden.
So, because poetry-core depends on isort (^4.3.21), version solving failed.

Rebased on master. The CI failure seems fixed now with poetry 1.1.0a3

I did a rebase and fixed conflicts, after which there are no more major changes left here anymore. Seems like the changes have been committed by another contributor after this PR was opened.

Hello @hukkinj1,

thanks a lot for your contribution!

I did a rebase and fixed conflicts, after which there are no more major changes left here anymore.

Yes, I think this is due to this PR #63

For the changes left in your PR please see my comment here about it: #63 (comment)

I will close your PR in favor of the above mentioned.

Thanks again 👍

fin swimmer