log_error (ActionController::Rescue)

    # File lib/action_controller/rescue.rb, line 65
          def log_error(exception) #:doc:
            ActiveSupport::Deprecation.silence do
              if ActionView::TemplateError === exception
                logger.fatal(exception.to_s)
              else
                logger.fatal(
                  "\n\n#{exception.class} (#{exception.message}):\n    " +
                  clean_backtrace(exception).join("\n    ") +
                  "\n\n"
                )
              end
            end
          end