Nix's design gives good guarantees about reproducibility. It may not be bit-perfect, but in general it is _very_ good. Maybe the Zero to Nix article on Caching,

Nix's design gives good guarantees about reproducibility. It may not be bit-perfect, but in general it is _very_ good. Maybe the Zero to Nix article on Caching, and its linked pages will help? https://zero-to-nix.com/concepts/caching https://zero-to-nix.com/concepts/caching The long and short of it is a merkle tree of hashed inputs :).