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

cvtk
0.3.6a0

This version was deleted from PyPI around 2024-03-23. Installing fails with:
$ pip3 install cvtk==0.3.6a0 ERROR: Could not find a version that satisfies the requirement cvtk==0.3.6a0
View other deleted versions of cvtk

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/2024-03-22/ \ cvtk==0.3.6a0
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:
cvtk-0.3.6a0-py3-none-any.whl (45.7KB)
cvtk-0.3.6a0.tar.gz (30.0KB)