If you encounter this issue inside of a Unit Test for a controller (functional test), it doesn't work to put the above code into any of your test methods. If you're using Rails-generated code, look for the line at the top of your controller_test class that looks like this: # Re-raise errors caught by the controller. class FooController; def rescue_action(e) raise e end; end and replace it with one that looks like this: class FooController; def rescue_action(ex) puts ex, ex.backtrace end; end Regards, Tad