I looked at nix a while ago, concluded the versioning/chesumming is - a given sum should represent kind-of the same thing, but can mean really anything. There

I looked at nix a while ago, concluded the versioning/chesumming is - a given sum should represent kind-of the same thing, but can mean really anything. There was even a post on how to have a stable version for a tracking branch. Now, I wouldn't mind, if it were explained exactly what guarantees the hashing provided, but there seemed to be pervasive misconception on what it provides.