require 'rubygems'
require 'pry'

module Kernel
  def raise(exception = RuntimeError, string = nil, array = caller)
    pry
  end
end

a = 5
raise "trouble"
a += 1

p a

# $ ruby test.rb
# Beginning Pry session for main
# pry(main)> a += 6
# => 11
# pry(main)> exit
# Ending Pry session for main
# 12
# $