Implement pep-503 - Simple Repository API

Feature

Basically the same request as: https://github.com/pytorch/pytorch/issues/25639

In short, lots of different tooling will benefit from being able to find precompiled wheels.

Motivation

I prefer using the poetry package manager due to various features it has over conda, but it lacks a --find-links equivalent. The prettiest solution then would be to use pep-503 as shown both here and and in the pytorch issue linked at the top.

Currently the way to install pytorch3d with poetry is to directly link a wheel.

Pitch

Like pytorch does it. Your implementation is not far off. For example: https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/py38_cu102_pyt1100/download.html do list versions, but the parent folder https://dl.fbaipublicfiles.com/pytorch3d/packaging/wheels/py38_cu102_pyt1100/ returns a Access Denied instead of listing a single link labeled "pytorch3d".

Related

#1073 will become simpler, since you can have multiple channels like pytorch has.