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

mocap-desktop-gui

This package was deleted from PyPI around 2026-02-13. Installing fails with:
$ pip3 install mocap-desktop-gui ERROR: Could not find a version that satisfies the requirement mocap-desktop-gui (from versions: none) ERROR: No matching distribution found for mocap-desktop-gui