How do I install ruby 2.0.0 correctly on Ubuntu 12.04?

Question

I have successfully installed rvm, but when I run the following commands

sudo apt-get update

Or:

rvm install 2         


        

Answer 1

From the travis-cli installation instructions for Ubuntu, the Brightbox Ruby NG(NextGeneration) ppa:

$ sudo apt-get install python-software-properties
$ sudo apt-add-repository ppa:brightbox/ruby-ng
$ sudo apt-get update
$ sudo apt-get install ruby2.1 ruby-switch
$ sudo ruby-switch --set ruby2.1