Ruby 2 for Debian Wheezy
Debian Wheezy provides Ruby version 1.9.3.
If you want to install a newer version, you need to do that manually.
But you don't want to mess with your system Ruby.
There are Ruby version managers like
rbenv to solve that problem.
Unfortunately, Debian's rbenv is out of date as well.
You will need to install a newer version of [rbenv] and the [ruby-build] plugin.