How can I install Ruby on Rails 3 on OSX?

Question

I got a White Macbook and I have to go to a conference in 10 hours but I'm having a lot of problems.

First, I wanted to have Rails 3, so I used MacPorts to install Ruby 1.8.7. It worked well ;) Then I was thinking I should install Rails 3, but no, no! It says:

$ sudo gem install rails --pre

ERROR: Error installing rails:


            activesupport requires Ruby version >= 1.8.7.

What should I do? I already have 1.8.7!

Answer 1

First you need to install RVM, then the latest version of Ruby. Next you'll set that version of Ruby as the default. Finally, you'll install Rails b3.

Install RVM (http://rvm.beginrescueend.com/rvm/install/):

bash < <( curl http://rvm.beginrescueend.com/releases/rvm-install-head )

Install the latest Ruby (http://rvm.beginrescueend.com/rubies/installing/):

rvm install ruby-head

You can check which versions you now have installed with:

rvm list

Set the latest version of Ruby as default (replace 'ruby-1.9.2-head' with desired version):

rvm ruby-1.9.2-head --default

Make sure things are up to day, then install the Rails beta:

gem update --system
gem install rails --pre

You may have to install some gem dependencies before Rails will install.