Man, forgetting to add my little error catching trick inside of one app I was writing made me realize how much I take such a simple trick for granted.

app = proc do |env|
  begin
    # Application code
  rescue Exception => e
    r = Rack::Response.new
    r.status = 500
    r.header["Content-Type"] = "text/plain"
    r.body = e.to_s << "\n" << "-" * e.to_s.length << "\n" << e.backtrace.join("\n")
    r.finish
  end
end

run app

I basically write all my rack code in a way similar to that. Normally I'll probably throw in another error catching level that catches special formated ErrorPage classes for things like NoPage to generate a 404. But this here is the big absolute fallback, if at any point inside of my code I make a mistake in syntax or anything this completely catches it, and renders the full error message and a full backtrace letting me actually see the error right away instead of looking through a horrid apache log.