I don't know why you are being downvoted, you are absolutely correct. If you need update something as important as a programming language version, you should be

I don't know why you are being downvoted, you are absolutely correct. If you need update something as important as a programming language version, you should be rebuilding the server entirely a la Immutable Infrastructure. If you're using Docker, it's as simple as building a new docker image with the latest Ruby version.