I was trying to install the new ruby 2.0.0 on my system but keep on getting error (I wish I saved the error message but I didn't, sorry!).

Next I went and tried updating Xcode and still can't install the new ruby 2.0.0. I ended up installing rvm like this;

    curl -L https://get.rvm.io | bash -s stable --ruby

And it worked! Woohoo!

But then referring to Daniel Kahoe of RailApps;

This guide shows how to install the most recent stable release (Rails 3.2.12), plus a version of Rails patched for Ruby 2.0 (Rails 3.2.13.rc2), and the newest version of Rails (Rails 4.0.0.beta1).


    $ rvm use [email protected]
    $ rails new myapp
    $ mv myapp myapp3.2.12
    $ rvm use [email protected]
    $ rails new myapp
    $ mv myapp myapp3.2.13

It seems like ruby 2.0.0 should (at least) be used in combination with Rails 3.2.13.rc2. Make sure to check that rvm gemset list and rvm list after installing ruby 2.0.0.

EDIT: Luckily I posted the error message on NatashaTheRobot's blog which means anyone with the same issue can check my post above.

$ rvm install ruby-2.0.0-p0
No binary rubies available for: osx/10.7/x86_64/ruby-2.0.0-p0.
Continuing with compilation. Please read 'rvm mount' to get more information on binary rubies.
Installing Ruby from source to: /Users/me/.rvm/rubies/ruby-2.0.0-p0, this may take a while depending on your cpu(s)...
ruby-2.0.0-p0 - #downloading ruby-2.0.0-p0, this may take a while depending on your connection...
Error running '/Users/me/.rvm/scripts/fetch http://ftp.ruby-lang.org/pub/ruby/2.0/ruby-2.0.0-p0.tar.bz2', please read /Users/me/.rvm/log/ruby-2.0.0-p0/fetch.log
There has been an error fetching the ruby interpreter. Halting the installation.
'rvm_codesign_identity' is not set, please set it in ~/.rvmrc