Error installing -dev

Hi,

I get the following error while installing RubyStack 2.1-0 dev for OSX.

http://i56.tinypic.com/2w65so6.png

And the same thing in the console:

bash-3.2$ rails
/Applications/rubystack-2.1-0/ruby/lib/ruby/site_ruby/1.9.1/rubygems.rb:10:in `require’: no such file to load — etc (LoadError)
from /Applications/rubystack-2.1-0/ruby/lib/ruby/site_ruby/1.9.1/rubygems.rb:10:in `<top (required)>’
from :235:in `require’
from :235:in `load_full_rubygems_library’
from :343:in `method_missing’
from /Applications/rubystack-2.1-0/ruby/bin/rails:19:in `’