> Just pin your nixpkgs version, and you can almost guarrante that you'll get the exact same build years later and you can still change parts of it if you need

> Just pin your nixpkgs version, and you can almost guarrante that you'll get the exact same build years later and you can still change parts of it if you need to. In theory. In practice, anything that doesn't hit the NixOS cache server will likely have been removed; it doesn't cache the build inputs, and links break all the time. On smaller timescales it's brilliant, though.