poetry show --outdated always lists mypy github repo

• Poetry version: 1.3.0
• Python version: 3.11.0
• OS version and name: Ubuntu 22.10 on WSL
• pyproject.toml: https://github.com/bszonye/bones/blob/bradd/warhammer/pyproject.toml

• I am on the latest stable Poetry version, installed using a recommended method.
• I have searched the issues of this repo and believe that this is not a duplicate.
• I have consulted the FAQ and blog for any relevant entries or release notes.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option) and have included the output below.

Issue

I have added mypy to my project as a github dependency:

mypy = {git = "git@github.com:python/mypy.git"}

When I check for outdated packages, Poetry always lists mypy. For example:

$ poetry show --outdated
mypy 1.0.0+dev.695ea3017fee084c9d2ec17d9b28f8af905e3b63 695ea30

That is already the HEAD version of mypy, and the Poetry update command (correctly) does nothing:

$ poetry update
Updating dependencies
Resolving dependencies... (3.3s)

Writing lock file

No dependencies to install or update

I can only speculate as to why the show command thinks this dependency is outdated. Perhaps it's because the mypy project reports a pre-release version; perhaps it's because they use a git commit in their version number, which has unstable ordering. In any case, I expect show --outdated to agree with update as to whether an update exists.

This is my first use of a github dependency, so it's possible that this is expected behavior, but I could not find a reference to the behavior in the Poetry docs or issue tracker.

Reproduce the behavior with the linked pyproject.toml, the GitHub-based mypy dependency, and Poetry 1.3.0 using both poetry show --outdated and poetry update. Compare how each command evaluates the current Git revision and determine what outcome makes the commands agree.