[Python] Unable to install our Poetry plugin: pip says there is no matching distribution found

I wrote a Poetry plugin and have it stored on a company PyPI repo. I am working on a Python project using Poetry and want to use my plugin. I though specifying the company repo with tool.poetry.source and then adding a line to

[tool.poetry.requires-plugins]
mycoolplugin = ">=1.0.3"


would be enough to get Poetry to install the plugin but it did not work as I expected.

I tried to install it manually and discovered there is a problem of some kind. I started with:

pip install mycoolplugin -i https://artifactory.compay.com/artifactory/api/pypi/thw-pypi/simple
Looking in indexes: https://artifactory.compay.com/artifactory/api/pypi/thw-pypi/simple
Collecting mycoolplugin
Downloading https://artifactory.compay.com/artifactory/api/pypi/thw-pypi/mycoolplugin/1.0.3/mycoolplugin-1.0.3-py3-none-any.whl (10 kB)
INFO: pip is looking at multiple versions of mycoolplugin to determine which version is compatible with other requirements. This could take a while.
Downloading https://artifactory.compay.com/artifactory/api/pypi/thw-pypi/mycoolplugin/1.0.2/mycoolplugin-1.0.2-py3-none-any.whl (10 kB)
ERROR: Cannot install mycoolplugin==1.0.2 and mycoolplugin==1.0.3 because these package versions have conflicting dependencies.

The conflict is caused by:
mycoolplugin 1.0.3 depends on poetry==2.1.3
mycoolplugin 1.0.2 depends on poetry==2.1.1

To fix this you could try to:
1. loosen the range of package versions you've specified
2. remove package versions to allow pip to attempt to solve the dependency conflict

ERROR: ResolutionImpossible: for help visit https://pip.pypa.io/en/latest/topics/dependency-resolution/#dealing-with-dependency-conflicts


But I am running in a venv with Poetry 2.1.3 so why not choose the correct one? There is no ambiguity.

poetry --version
Poetry (version 2.1.3)


So, I thought perhaps pip cannot tell what Poetry is already there so I ran it with Poetry instead, sadly this command line gives the exact same results:

poetry run python3 -m pip install mycoolplugin -i https://artifactory.compay.com/artifactory/api/pypi/thw-pypi/simple`


So, then I tried installing the specific version I wanted:

poetry run python3 -m pip install mycoolplugin==1.0.3 -i https://artifactory.company.com/artifactory/api/pypi/thw-pypi/simple
Looking in indexes: https://artifactory.company.com/artifactory/api/pypi/thw-pypi/simple
Collecting mycoolplugin==1.0.3
Using cached https://artifactory.company.com/artifactory/api/pypi/thw-pypi/mycoolplugin/1.0.3/mycoolplugin-1.0.3-py3-none-any.whl (10 kB)
INFO: pip is looking at multiple versions of mycoolplugin to determine which version is compatible with other requirements. This could take a while.
ERROR: Could not find a version that satisfies the requirement poetry==2.1.3 (from mycoolplugin) (from versions: none)
ERROR: No matching distribution found for poetry==2.1.3


What is wrong here?

The mycoolplugin project has a pyproject.toml file with:

[project]
name = "mycoolplugin"
...
dependencies = [ "poetry (==2.1.3)", ...
...
[build-system]
requires = ["poetry-core>=2.0"]

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