SolverProblemError with multiple constraints that do not intersect

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: MacOSX
• Poetry version: 0.12.8
• Link of a Gist with the contents of your pyproject.toml file: pyproject.toml

Issue

I would like to list pylint as a dependency of my tool. pylint^1 supports Python 2 and pylint^2.0 supports Python 3. From the documentation, I assumed the following would work:

pylint = [
  { version = "^2", python = "^3" },
  { version = "^1", python = "^2" }
]

But I get a SovlerProblemError that says Because phidias depends on both pylint (^2) and pylint (^1), version solving failed.

I have the full output in the Gist. It has the following in it:

   1: fact: phidias depends on pylint (^2)
   1: fact: phidias depends on pylint (^1)

That shouldn’t be true as I can’t be running a Python interpreter that validates both of the Python semantic versions ^2/^3.

[agilgur5]

Seems like this may have regressed? On Poetry 0.12.17 (and Python 3.7.4):

pytest = [
    {version = "^5.1", python = "^3.5"},
    {version = "~4.6", python = "~3.4"}
]

The Python versions don’t overlap, but getting this same error:

[SolverProblemError]
Because package-name depends on both pytest (^5.1) and pytest (~4.6), version solving failed.

EDIT: seems like this may only be an issue in dev dependencies now? When I moved it to main dependencies, the SolverProblemError disappeared. Might be worth opening a new issue…

[agilgur5]

@peterdeme and anyone else reading here, looks like a duplicate issue of this was raised in #1480 and later resolved in #1482, which was just released yesterday in 1.0.0b3. Not sure if this will come out in a stable release, but 1.0.0b3 does seem to fix it, as far as I can tell.

Found this out after I wrote a failing test case for this in #1509 only to find out it had a merge conflict and was just recently resolved 😅