// create a custom logger that writes to a file $logFile = '/var/log/myapp.log'; $logger = new \Monolog\Logger('myapp'); $logger->pushHandler(new \Monolog\Handler\StreamHandler($logFile, \Monolog\Logger::DEBUG)); // configure Propel to use the custom logger \Propel\Runtime\Propel::setLogger($logger);In this example, we create a custom logger using the Monolog library, which is a popular logging library for PHP. We then configure Propel to use the custom logger by calling the setLogger method and passing in the logger object. This example assumes that the Monolog library has been installed and is available in your project. Package library: Propel ORM