Bug or messaging problem?

• I have searched the issues of this repo and believe that this is not a duplicate.
• I have searched the documentation and believe that my question is not covered.

Issue

I'm not sure if this is a bug or a problem with the messaging in Poetry, but it's something I see a lot, and it's rather hard to search for in the issues so sorry if it's a dupe. Here's the problem...

I have a pyproject.toml that includes this in dev dev dependencies...

[tool.poetry.dev-dependencies]
faker = "*"
mixer = "*"

I discover that mixer is pretty much abandoned and has a bug that breaks my tests, but all my tests depend on it, so I fork the repo and try to switch to installing from my fork by editing the pyproject.toml

[tool.poetry.dev-dependencies]
faker = "*"
mixer = {path = "src/mixer/"}

I then run poetry install and I get this output...

[SolverProblemError]
Because no versions of mixer match !=6.1.3
 and mixer (6.1.3) depends on Faker (0.9.1), every version of mixer requires Faker (0.9.1).
So, because no versions of faker match 0.9.1
 and myproject depends on mixer (*), version solving failed.

This is telling me that there is no version 0.9.1 of faker. So, I check the faker release history and there it is, 0.9.1

Then I remember how often Poetry does this to me, and instead of editing the pyproject.toml I run poetry add faker="0.9.1" and get this output...

Updating dependencies
Resolving dependencies... (4.7s)

Writing lock file


Package operations: 0 installs, 3 updates, 1 removal

  - Updating text-unidecode (1.3 -> 1.2)
  - Updating faker (4.0.3 -> 0.9.1)
  - Updating mixer (5.5.7 -> 6.1.3 src/mixer)
  - Removing fake-factory (0.5.7)

So, if Faker 0.9.1 definitely exists, and poetry is perfectly able to resolve the dependencies, why does it tell me that it can't in the first message?

Reproduce the dependency-resolution messages using the pyproject.toml examples and the poetry install and poetry add commands shown. Trace how the local mixer path dependency and Faker constraints are reported, then compare both outputs. Done means the reported conflict accurately explains why resolution fails or distinguishes the messaging problem.