Rack::ShowStackDeck catches all exceptions raised from the app it wraps. It shows a useful backtrace with the sourcefile and clickable context, the whole Rack environment and the request data.
Be careful when you use this on public-facing sites as it could reveal information helpful to attackers.
Rack::ShowStackDeck is based on, and functionally very similar to, Rack::ShowExceptions -- the key difference is that it uses the StackDeck library to show the full cross-language backtrace, where relevant.
Generated with the Darkfish Rdoc Generator 2.