[manume]

> Sadly, 9 out of 10 environments lack a Ruby interpreter out of the box.

Please name those 10 environments you are talking about. In my experience, a reasonably recent Ruby version is present almost everywhere.

> add 5 minutes to your docker build

Why on earth would it take 5 minutes to install anything? If you install Ruby through a package manager (it's present in pretty much all of them: https://www.ruby-lang.org/en/documentation/installation/#pac...) it takes only seconds.