Swat/SwatError.php
public function log()
    {
        if (count(self::$loggers) === 0) {
            error_log($this->getSummary(), 0);
        } else {
            foreach (self::$loggers as $logger) {
                $logger->log($this);
            }
        }
    }
public function log()
    {
        if (count(self::$loggers) === 0) {
            error_log($this->getSummary(), 0);
        } else {
            foreach (self::$loggers as $logger) {
                $logger->log($this);
            }
        }
    }
public function log ( ) { if ( count ( self :: $ loggers ) === 0 ) { error_log ( $ this -> getSummary ( ) , 0 ) ; } else { foreach ( self :: $ loggers as $ logger ) { $ logger -> log ( $ this ) ; } } }
Logs this error

The error is logged to the webserver error log.
Logs this error