It's a good idea to be caching sdists and wheels — for resilience against PyPI downtime, for left-pad scenarios, and even just good netiquette — and for package

It's a good idea to be caching sdists and wheels — for resilience against PyPI downtime, for left-pad scenarios, and even just good netiquette — and for packages that don't have a wheel for your environment, you can fairly easily build that wheel yourself and stick it into the cache.