• 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: Ubuntu 18.04 and MacOs 10.15.7

• Poetry version: 1.1.*.

• Link of a Gist with the contents of your pyproject.toml file: https://gist.github.com/lgelmi/82142f2e092b698b8c06de6302401c9b

Issue

Poetry fails resolving dependencies with the following message:

...
   1: conflict: package_b (2.4.1 git rev master) depends on package_a (0.1.15 git rev master)
   1: ! not package_a (0.1.15 git rev master) is satisfied by package_a (0.1.15 git branch master)
   1: ! which is caused by "package_c depends on package_a (0.1.15 git branch master)"
   1: ! thus: package_b is forbidden
   1: ! package_b (2.4.1 git rev master) is satisfied by package_b (2.4.1 git branch master)
   1: ! which is caused by "package_c depends on package_b (2.4.1 git branch master)"
   1: ! thus: version solving failed
...

As you can see package_c depends both on a and b, and b depends on a.
This should not cause any error since they do not conflict and, as a matter of fact, in version 1.0.* it did not.

Sadly, the repos are private and I cannot provide them, but they are python packages managed with poetry themselves.