try to clarify when to use ruby_bug
try to clarify when to use ruby_bug

eregon/rubyspec,eregon/rubyspec,sgarciac/spec,ruby/spec,ruby/rubyspec,ruby/spec,ruby/spec,nobu/rubyspec,ruby/rubyspec,sgarciac/spec,sgarciac/spec,eregon/rubyspec,nobu/rubyspec,nobu/rubyspec