Nothing known about… when trying ri String#upcase Ruby

Question

I have just installed the RVM and I am reading The Well-Grounded Rubyist book. In the first chapter I am supposed to try ri String#upcase to view documentation

Answer 1

It might be that docs aren't working because you're using the latest ruby version, 2.1, in which rvm has some problems. It doesn't generate docs, thus you can't retrieve the docs with ri.

**Error: **

Your ruby version 2.1.2 is not supported, only 1.8.7, 1.9.2, 1.9.3, 2.0.0