I had installed ruby gems (rubygems) using the apt package management system, which is the recommended way, but ran into a problem when I wanted to install rails 3:
Error installing rails:
i18n requires RubyGems version >= 1.3.6
The solution was to install the latest version of gems from its source:
tar xvfz rubygems-1.3.7.tgz
sudo ruby setup.rb
Now it works like a charm:
sudo gem install rails
rails new testapp
That's it for today. Thanks for stopping by.
PS: Instead of using the system wide ruby gems (like I just showed you) you can also use the RVM (Ruby Version Manager), which lets you use different versions of ruby and gems for each ruby/rails project.