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

bigdl-core-xe-addons-21
2.6.0b20240828

This version was deleted from PyPI around 2024-09-13. Installing fails with:
$ pip3 install bigdl-core-xe-addons-21==2.6.0b20240828 ERROR: Could not find a version that satisfies the requirement bigdl-core-xe-addons-21==2.6.0b20240828

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/2024-09-12/ \ bigdl-core-xe-addons-21==2.6.0b20240828
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)