# Using Xdebug The default development image is shipped with [Xdebug](https://xdebug.org/), a popular debugger and profiler for PHP. Because it has a significant performance overhead, the step-by-step debugger is disabled by default. It can be enabled by setting the `XDEBUG_MODE` environment variable to `debug`. On Linux and Mac: ``` XDEBUG_MODE=debug docker compose up -d ``` On Windows: ``` set XDEBUG_MODE=debug&& docker compose up -d&set XDEBUG_MODE= ``` ## Debugging with Xdebug and PHPStorm First, [create a PHP debug remote server configuration](https://www.jetbrains.com/help/phpstorm/creating-a-php-debug-server-configuration.html): 1. In the `Settings/Preferences` dialog, go to `PHP | Servers` 2. Create a new server: * Name: `symfony` (or whatever you want to use for the variable `PHP_IDE_CONFIG`) * Host: `localhost` (or the one defined using the `SERVER_NAME` environment variable) * Port: `443` * Debugger: `Xdebug` * Check `Use path mappings` * Absolute path on the server: `/srv/app` You can now use the debugger! 1. In PHPStorm, open the `Run` menu and click on `Start Listening for PHP Debug Connections` 2. Add the `XDEBUG_SESSION=PHPSTORM` query parameter to the URL of the page you want to debug, or use [other available triggers](https://xdebug.org/docs/step_debug#activate_debugger) Alternatively, you can use [the **Xdebug extension**](https://xdebug.org/docs/step_debug#browser-extensions) for your preferred web browser. 3. On command line, we might need to tell PHPStorm which [path mapping configuration](https://www.jetbrains.com/help/phpstorm/zero-configuration-debugging-cli.html#configure-path-mappings) should be used, set the value of the PHP_IDE_CONFIG environment variable to `serverName=symfony`, where `symfony` is the name of the debug server configured higher. Example: ```console XDEBUG_SESSION=1 PHP_IDE_CONFIG="serverName=symfony" php bin/console ... ``` ## Troubleshooting Inspect the installation with the following command. The Xdebug version should be displayed. ```console $ docker compose exec php php --version PHP ... with Xdebug v3.x.x ... ```