You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

arts
2025.4.12

This version was deleted from PyPI around 2026-04-02. Installing fails with:
$ pip3 install arts==2025.4.12 ERROR: Could not find a version that satisfies the requirement arts==2025.4.12
View other deleted versions of arts

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2026-04-01/ \ arts==2025.4.12
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)

Or, download files manually

And install manually via pip:
arts-2025.4.12-py3-none-any.whl (15.9KB)
arts-2025.4.12.tar.gz (17.7KB)