require-prof allows you to easily profile your Ruby project's imports:

   irb -r require-prof -r <path to your code>

Then just run

   RequireProf.print_timing_infos

to see the time breakdown of your requires in chronological order. Run

   RequireProf.print_timing_infos_for_optimization

to see the time breakdown by amount of time spent.

If you set the environment variable RUBY_REQUIRE_PRINT_LIVE to 'true', require-prof will print out import timing information as it happens.