Has there been discussion about setting up a binary cache that can be used for packages in staging?
I would find it very useful for bisecting and testing. If ofborg can be taught to use it, perhaps it could also speed up CI against the staging branch. A LRU cache of some sort would be ideal IMO.
I’m sorry. The main purpose of staging is… not to build everything on every commit in there (on Hydra), because that would be very expensive.
https://hydra.nixos.org/jobset/nixos/staging-small
exists, though running irregularly. You could still use it for your initial bisection steps manually. (Everything built on Hydra gets to cache.nixos.org)
Maybe I should add that Hydra.nixos.org is rarely idling. Most of the time it has thousands of builds queued for each of its platforms. So it’s mostly a zero-sum game. Moreover, we seem to be at a point where adding more builders to Hydra doesn’t increase the total practical throughput anymore.
Thanks for the context. I thought maybe that the staging-next jobset runs were somehow not being cached, because often when I build staging locally I end up needing to build the world, but I guess that is because the world changes that fast.
staging-next is built and cached, staging isn’t (at least not regularly)
staging-next contains mostly builds that get into master soon, so it doesn’t really help with this problem.