I wonder about installing the latest version of Ruby on Ubuntu 9.04. Now I can run through the ./configure and make stuff fine, but what I wonder about: how to avoid conflicts with the packaging system? For example if some other package I install depends on Ruby, wouldn't the package manager install the (outdated) Ruby package and in the worst case overwrite my files?
So I think I need some way to tell Ubuntu that Ruby is in fact already installed?
Save yourself the headache and use RVM (Ruby Version Manager)
Keep in mind, Rails 3 works best with Ruby 1.9.2. Ruby 1.9.2 fixes up quite a few bugs in 1.9.1 and is preferable to running 1.9.1.
With RVM installing 1.9.2 is a breeze.