Ruby: require vs require_relative - best practice to workaround running in both Ruby <1>=1.9.2

Question

What is the best practice if I want to require a relative file in Ruby and I want it to work in both 1.8.x and >=1.9.2?

I see a few options:

Answer 1

Another option is to tell the interpreter which paths to search

ruby -I /path/to/my/project caller.rb