Package installation failure and rollback options

I'm trying to understand how the creation of packages (rpm, deb, dpkg) work and what the architecture supports and doesn't. Right now I struggle figuring out what happens when the installation or upgrade of a package fails at different points of the process -ie, error on a scriptlet, not enough disk space (is this checked before starting?)-. From my current understanding, there's no automatic rollback to a previous working version if there was any. So my question would be, how do packages deal with this scenarios? Aren't scriptlets used at all to backup files and restore them post transaction if some error occurred? (I coudln't find examples so far) Thank you.