module Roda::RodaPlugins::ErrorHandler::InstanceMethods

def call

the error handler.
If an error occurs, set the response status to 500 and call 
def call
  super
rescue *opts[:error_handler_classes] => e
  @_response.send(:initialize)
  @_response.status = 500
  res = _call{handle_error(e)}
  begin
    _roda_after(res)
  rescue => e2
    if errors = env['rack.errors']
      errors.puts "Error in after hook processing of error handler: #{e2.class}: #{e2.message}"
      e2.backtrace.each{|line| errors.puts(line)}
    end
  end
  res
end

def handle_error(e)

behavior.
the plugin without installing an error handler doesn't change
By default, have the error handler reraise the error, so using 
def handle_error(e)
  raise e
end