# File src/ruby_supportlib/phusion_passenger/ruby_core_enhancements.rb, line 44
  def backtrace_string(current_location = nil)
    if current_location.nil?
      location = nil
    else
      location = "in #{current_location} "
    end
    current_thread = Thread.current
    if !(thread_id = current_thread[:id])
      current_thread.to_s =~ /:(0x[0-9a-f]+)/i
      thread_id = $1 || '?'
    end
    if thread_name = current_thread[:name]
      thread_name = "(#{thread_name})"
    end
    return "*** Exception #{self.class} #{location}" <<
      "(#{self}) (process #{$$}, thread #{thread_id}#{thread_name}):\n" <<
      "\tfrom " << backtrace.join("\n\tfrom ")
  end