To use debug, just insert " require ‘debug‘ " in which you want to debug.

you can list code piece with list command, and user ‘n‘ command to execute next line. you also cound print all local value with ( v l ) command , and print all global variable with ( g l) command.

and finally , user ‘c‘ command to complete execute rest code.

and pp is pretty print .

ruby_debug笔记