How do I debug 3 gem rails?

Question

I created a gem / engine based on this tutorial:

http://www.themodestrubyist.com/2010/03/05/rails-3-plugins---part-2---writing-an-engine/

However, I get an error when trying to use the gem in a newly created application. When I try to access the application, I get a "Routing error - undefined method` sub" for nil: NilClass.

The only thing I see in the log file is the same error. There is no trace trace / debug trace, so it’s hard to understand where the error comes from. Ideally, I would like to see a "gem" stack trace, but it doesn't seem that the rails are debugging errors coming from outside the application?

I am using rvm, ruby ​​1.9.2, rails 3.0.1.

Here is my config / routes.rb file from the pearl, although I don't think this is a routing error, as the debug message says.

Rails.application.routes.draw do resources :pictures, :controller => 'morph/pictures' end 

Any suggestions?

Answer 1

If you uncomment

 Rails.backtrace_cleaner.remove_silencers! 

in config/initializers/backtrace_silencers.rb it will display a more complete stack. It worked for me.

Answer 2

Is there a backtrace in the console?

If you cannot find any additional output, you can place the “debugger” instruction somewhere near the start of your application and go through the source code until an error occurs.

You can do the same with the gem / plugin source.

Edit: the author seems to have a link to the demo code at the bottom of the article. It may also be helpful.