3 ms·

This is exactly what Nix does, if I understand correctly: the "mirror" is cache.nixos.org as mentioned in XorNot's reply to the same parent post.

• aidenn0 10mo ago
  I'm about 80% certain that cache.nixos.org caches the results of the builds, not the input sources.
  • MarsIronPI 10mo ago
    I think it does both, at least for some sources. After all, sources are derivations too.
    • sestep 10mo ago
      This is correct; in Nix lingo these are referred to as "fixed output derivations". For some other interesting context, see this Nix forum post from last year in which they discussed deleting some stuff from cache.nixos.org to save money, but were clear that they'd keep all fixed output derivations and only delete other things that aren't derivable from those: https://discourse.nixos.org/t/upcoming-garbage-collection-for-cache-nixos-org/39078 https://discourse.nixos.org/t/upcoming-garbage-collection-fo...