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

passagemath-frobby
10.4.66

This version was deleted from PyPI around 2025-11-02. Installing fails with:
$ pip3 install passagemath-frobby==10.4.66 ERROR: Could not find a version that satisfies the requirement passagemath-frobby==10.4.66