[SolverProblemError] Wrong dependency solving

[Olegt0rr]

• 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: macOS 11.2.3 (20D91)
• Poetry version: 1.1.5
• pyproject.toml: https://gist.github.com/Olegt0rr/a464bc0f8fc6db6c87d9ba547273f8cb#file-pyproject-toml
• Log output: https://gist.github.com/Olegt0rr/a464bc0f8fc6db6c87d9ba547273f8cb#file-console-log

Actions

1. Create empty project
2. Add dependency pymongo = {version = "3.11.3", extras = ["srv"]}
3. Run poetry add dnspython

Expected output:

# pyproject.toml

[tool.poetry.dependencies]
python = "^3.8"
pymongo = {version = "3.11.3", extras = ["srv"]}
dnspython = "~1.16"

Real output

poetry add dnspython     
Using version ^2.1.0 for dnspython

Updating dependencies
Resolving dependencies... (0.0s)

[SolverProblemError]
Because tree depends on pymongo (3.11.3) which depends on dnspython (>=1.16.0,<1.17.0), dnspython is required.
So, because tree depends on dnspython (^2.1.0), version solving failed.

Rich log: https://gist.github.com/Olegt0rr/a464bc0f8fc6db6c87d9ba547273f8cb#file-console-log

[finswimmer]

Hello @Olegt0rr,

it seems that the resolver tries to find a solution for the latest major version of the dependency only and gives up if it cannot find a solution. Giving poetry a hint where to start searching works as a workaround, e.g. poetry add "dnspython=~1.16".

fin swimmer

[Olegt0rr]

@finswimmer,
Thanks for manual workaround, but it so weird for me to make hints about version resolving :)
Still waiting for fixing this behaviour

[dimbleby]

another duplicate of #707

[neersighted]

Good catch.

[github-actions]

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