Test against 3.15 RCs

[simonw]

See https://simonwillison.net/2026/Sep/1/python-315-rc-2/

[simonw]

test-llm-load-plugins.sh is currently failing:

ERROR: Failed to build 'scikit-learn' when installing build dependencies for scikit-learn

Awaiting a PyPI wheel for scikit-learn on Python 3.15:

• MNT Python 3.15 support scikit-learn/scikit-learn#34652

[lesteve]

Hi there as replied in scikit-learn/scikit-learn#34652 (comment) you can use our development wheel depending on your projects' tradeoffs:

pip install --pre --extra-index https://pypi.anaconda.org/scientific-python-nightly-wheels/simple scikit-learn

And I had no idea that scikit-learn was a dependency of llm now I am curious to understand what you are using scikit-learn for 👀.