From: Justin Collins <collinsj@...>
Date: 2006-06-20T08:32:53+09:00
Subject: Re: Where's the backtrace?

lists wrote:
> I'm probably misunderstanding the way things are supposed to work.  
> Here's what I'm seeing:
>
> $ cat lib.rb
> class MyClass
>         def throws_an_exception
>                 self.non_existent_method
>         end
> end
>
> if __FILE__ == $0
>         MyClass.new.throws_an_exception
> end
> $ ruby lib.rb
> lib.rb:3:in `throws_an_exception': undefined method 
> `non_existent_method' for #<MyClass:0x255bc> (NoMethodError)
>         from lib.rb:8
>
> So far, this is what I expect. Now consider:
>
> $ cat the_test.rb
> require './lib'
>
> begin
>         MyClass.new.throws_an_exception
> rescue => e
>         puts e
> end
> $ ruby the_test.rb
> undefined method `non_existent_method' for #<MyClass:0x2560c>
>
> I don't get the rest of the backtrace (line number, etc.) unless I use 
> the -d flag:
>
> $ ruby -d the_test.rb
> Exception `NoMethodError' at ./lib.rb:3 - undefined method 
> `non_existent_method' for #<MyClass:0x2560c>
> undefined method `non_existent_method' for #<MyClass:0x2560c>
>
> Is there a way to get the "full" backtrace when calling "the_test.rb" 
> without using the -d flag?  I hope this makes sense.
>
> Thanks,
> Ryan
>
>
Check out the documentation for the Exception class:

http://ruby-doc.org/core/classes/Exception.html


There is a method for retrieving the backtrace. Try this:

begin
        MyClass.new.throws_an_exception
rescue => e
        puts e
        puts e.backtrace.join("\n")
end


-Justin