uv add onnxruntime fails to fetch latest version of package compatible with my environment's Python

[sebastian-correa]

When adding onnxruntime in Python 3.9, uv fails to resolve 1.19.2 and instead fails. onnxruntime 1.20.0 dropped support for Python 3.9. Could this be related to onnxruntime as poetry add also "fails" (it installs a wrong version and explodes in the process)?

To reproduce, do:

❯ mkdir onnxruntime-test
❯ cd onnxruntime-test
❯ uv init --python=3.9
Initialized project `onnxruntime-test`
❯ uv add --python=3.9 onnxruntime
Using CPython 3.9.20
Removed virtual environment at: .venv
Creating virtual environment at: .venv
Resolved 11 packages in 16ms
error: Distribution `onnxruntime==1.20.1 @ registry+https://pypi.org/simple` can't be installed because it doesn't have a source distribution or wheel for the current platform

Running uv in macOS 15.1 (24B83). uv version is:

❯ uv --version
uv 0.5.4 (c62c83c37 2024-11-20)

[charliermarsh]

I think the problem is that they don't have requires-python = ">=3.9", so from a metadata perspective, it "looks like" they still support Python 3.9. I could see us backtracking here, though, such that if there's no source distribution, we look for the next version with a matching wheel, if some Python versioning are missing.

In the meantime, you probably want to do something like:

[project]
...
dependencies = ["onnxruntime>=1.20.1 ; python_version > '3.9'", "onnxruntime<1.20.1 ; python_version <= '3.9'"]

[charliermarsh]

This is roughly the same as #5182, but for Python version, not platform (which is more tractable).

[sebastian-correa]

Thanks for the reply! I figured it had something to do with this, and I tried to find the spot where they defined compatible Python versions but couldn't.

Can I help somehow? I don't know a single thing about rust or uv's inner workings but if I can be of help somehow, please let me know!