How to install different Ruby versions with chruby

installing_ruby_versions_with_chruby.md

Managing Ruby Versions with chruby

So I'm always forgetting how to do this! I guess I'm only ever updating Ruby versions every now and then.

Checking out which Ruby versions chruby has access to

$ chruby will display your installed rubies and show you the version you're currently using in your shell.

   ruby-2.1.2
   ruby-2.2.1
   ruby-2.3.1
   ruby-2.3.3
   ruby-2.4.1
 * ruby-2.4.4
   ruby-2.5.0

Downloading the new Ruby

$ ruby-install ruby 2.4.5 will download the version you're after, just pass in the version number as the second argument (after ruby).

Gotchas

• Make sure the version is installed in ~/.rubies and you can see a directory for the newly installed version
• Restart the shell so that your new version is loaded

Switching to the desired Ruby

Switch to the version you're after once it's installed by running chruby with the version number $ chruby 2.4.5

FWIW I came across an issue where readline was out of date in the Ruby version I was on (an older version).
You sometimes need to update Rubies so that stuff with work! I just re-installed, and good to go!