When having a git dependency, Poetry fails with SolverProblemError while trying to run $ poetry install twice

• 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: Debian Booster; Windows 10

• Poetry version: 1.0.0b1 as installed by pip for python 3.8.0b4; 0.12.17

• Link of a Gist with the contents of your pyproject.toml file: link

Issue

Run

$ poetry new a
$ cd a
$ vim pyproject.toml

Add a single dependency like this:

attrs = { git = "https://github.com/python-attrs/attrs.git", rev = "daf2bc8182a681ed0c85271bafbd24c2ca5ea70b" }

Run $ poetry install. Observe that correct version of attrs is installed

- Installing attrs (19.2.0.dev0 daf2bc8)

Run the same command again: $ poetry install. Observe that Poetry fails with:

[SolverProblemError]
Because no versions of pytest match >=3.0,<3.10.1 || >3.10.1,<4.0
 and pytest (3.10.1) depends on attrs (>=17.4.0), pytest (>=3.0,<4.0) requires attrs (>=17.4.0).
So, because no versions of attrs match >=17.4.0
 and b depends on pytest (^3.0), version solving failed.

Same problem manifests itself for this version of attrs as a path dependency. I tested a few other libraries and they don’t seem to be affected with the exception of mypy, which i believe is due to #611. #743 is a possibly related issue.

The problem can be mitigated by erasing the virtual environment removing poetry.lock.

[sdispater]

@oakkitten It will be fixed in the next beta release which should be out today or tomorrow.

[oakkitten]

looks like this issue is fixed in 1.0.0b5!