# File src/ruby_supportlib/phusion_passenger/debug_logging.rb, line 52
    def self.log_file=(filename)
      if filename && filename.empty?
        @@log_filename = nil
      else
        @@log_filename = filename
      end
      @@log_device.close if @@log_device && !@@log_device.closed?
      @@log_device = nil
    end