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

gs-include
0.26.0a20231206

This version was deleted from PyPI around 2023-12-18. Installing fails with:
$ pip3 install gs-include==0.26.0a20231206 ERROR: Could not find a version that satisfies the requirement gs-include==0.26.0a20231206
View other deleted versions of gs-include

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/2023-12-17/ \ gs-include==0.26.0a20231206
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:
gs_include-0.26.0a20231206-py2.py3-none-any.whl (27.5MB)
gs_include-0.26.0a20231206-py2.py3-none-macosx_12_0_x86_64.whl (31.1MB)