RubyGem update on Leopard

I have a RubyGem version 1.2.0 installed on Leopard. If you would like to update RubyGems to a newer version, the RubyGem user guide suggests for modern versions( >0.8.5 ) can use the following command:

gem update --system

But, console told me the 1.2.0 is the latest version - Nothing to update! The work around is to use install rubygem-update:

gem install rubygems-update
update_rubygems

Check installed version:

MBP:~ Jay$ gem --version
1.3.1

So now, I’m able to pull the latest rSpec plugin into my Rails project.