I used "-d" option to run ruby. However, following errors are occured. What is the menning?
Exception `LoadError' at c:/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:871 - no such file to load -- rubygems/defaults/operating_system Exception `NoMethodError' at c:/ruby/lib/ruby/1.8/rational.rb:78 - undefined method `gcd' for Rational(1, 2):Rational debug_mode