Unable to require RubyGems

I have RubyGems version 1.8.5 and Ruby version 1.8.7. My problem is that even after installing gems I am not able to require it. On the command line typing gem list --local gives:

bundler (1.0.15)
hpricot (0.8.4)
json (1.5.1)开发者_开发问答
redcarpet (1.17.1)

But this does not help.

begin
    require 'bundler'
    rescue LoadError => boom
        warn "Bundler not found"
    exit 0
end
# I get Bundler not found

I am running Ubuntu Natty 32-bit

UPDATE: After requiring RubyGems in irb I get a much informable error i.e.

LoadError: no such file to load -- bundler
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:36:in `require'
from (irb):3
from :0

---

Bundler does not provide bundler as a file you require directly. Instead you have to require bundler/setup, as shown in the documentation:

http://gembundler.com/

require "rubygems"
require "bundler/setup"

# require your gems as usual
require "nokogiri"

Also, on Ruby 1.8.7, you still need to require 'rubygems'

Hope that helps

---

Are you sure you've loaded rubygems? What happens when you enter an irb session and type require 'rubygems'?