See how long it takes to load each dependency

dependency_requires.rb

# These don't load properly with this technique, so we preload them if the app
# needs them. :-(
require 'psych'
require 'bigdecimal'

alias zomg_require require

auto_create_hash = proc do |h,k|
  hash = h[k] = {}
  hash.default_proc = auto_create_hash
  hash
end
$file_load_times = Hash.new(&auto_create_hash)
$current_file_hierarchy = []

def require file
  $current_file_hierarchy.push file
  start = Time.now
  result = zomg_require file
  finish = Time.now
  hash = $current_file_hierarchy.reduce($file_load_times) do |current, file|
    current[file]
  end
  $current_file_hierarchy.pop
  hash[file] = ((finish - start) * 1000).round(3)

  result
end