2 points
They’re promising to give notice, but it’s just not a good situation.
cache.nixos.org keeps all sources so once hydra has ingested something it’s not going away unless nixos maintainers want it to. The policy for decades was simply “keep all derivations” but in the interest of space savings it has recently been decided to do a gc run, meaning that 22 year old derivations will still available but you’re going to have to build them from the cached source, the pre-built artifacts will be gone.
