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

flatpack
3.1.251

This version was deleted from PyPI around 2025-02-15. Installing fails with:
$ pip3 install flatpack==3.1.251 ERROR: Could not find a version that satisfies the requirement flatpack==3.1.251
View other deleted versions of flatpack

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/2025-02-14/ \ flatpack==3.1.251
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:
flatpack-3.1.251-py3-none-any.whl (19.7KB)
flatpack-3.1.251.tar.gz (17.3KB)