class Sinatra::ShowExceptions

def call(env)
  @app.call(env)
rescue Exception => e
  errors, env["rack.errors"] = env["rack.errors"], @@eats_errors
  if respond_to?(:prefers_plain_text?) and prefers_plain_text?(env)
    content_type = "text/plain"
    body = [dump_exception(e)]
  else
    content_type = "text/html"
    body = pretty(env, e)
  end
  env["rack.errors"] = errors
  [500,
   {"Content-Type" => content_type,
    "Content-Length" => Rack::Utils.bytesize(body.join).to_s},
   body]
end