RailsDebugging

Rails Debugging HOWTO

This is a really short, yet essential, introduction as to how to use the debugger in rails. It is assumed that you have a console showing you the mongrel server output and you know at what line your code fails. Also, you should have 'ruby-debug' installed on your machine (do a 'gem install ruby-debug', if you don't). For simplicity, assume there is an error on line 21 in file 'rubrics_controller'. Here is what you would do:

1. Add the word 'debugger' on line 20 (one line prior to the erroneous line) in 'rubrics_controller.rb'
2. Reload the page giving you the error (it will stop executing right at the line you added 'debugger')
3. Go to the console window where your mongrel server output is printed and type 'irb'
4. That's it! You have a debugging console ready and you are save typing your

debugging commands, now (see the [[Rails debugging guide | http://guides.rubyonrails.org/debugging_rails_applications.html]] for more information)

5. Once you have finished debugging, type 'quit', hit return, remove the line 'debugger' and type 'continue' to resume your mongrel server.

Enjoy, debugging!