my macbook is OSX EI Capitan. It has Apple pre-installed universal Ruby version 2.0.0.
Now, I want to use latest Ruby 2.3.0. I managed to use rvm to install Ruby 2.3.0. I see the following message after rvm finished installing ruby 2.3.0:
Ruby was built without documentation, to build it run: rvm docs generate-ri
/Users/John/.rvm/bin/rvm: line 66: shell_session_update: command not found
Creating alias default for ruby-2.3.0...
* To start using RVM you need to run `source /Users/John/.rvm/scripts/rvm`
in all your open shell windows, in rare cases you need to reopen all shell windows.
To switch to using 2.3.0, do
rvm use 2.3.0
To make it default, do
rvm use --default 2.3.0