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

upathlib
0.8.8b3

This version was deleted from PyPI around 2023-12-27. Installing fails with:
$ pip3 install upathlib==0.8.8b3 ERROR: Could not find a version that satisfies the requirement upathlib==0.8.8b3
View other deleted versions of upathlib

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/2023-12-25/ \ upathlib==0.8.8b3
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:
upathlib-0.8.8b3-py3-none-any.whl (34.4KB)
upathlib-0.8.8b3.tar.gz (30.3KB)