I was able to set up a php web app debugger in PHPStorm by simply tying it to my localhost at a specific port and everything works fine. However for that to work I need to first run this command on the shell:
php app/console server:run --env=dev
/usr/local/Cellar/php54/5.4.28/bin/php -S localhost:8000 -t /project/root/directory
php app/console server:run --env=dev -S localhost:8000 -t /project/root/directory
You shouldn't create a run configuration at all, just to click on the listen button:
Configure xdebug to attempt to debug every single script (
xdebug.remote_autostart = 1 and
xdebug.remote_enable = 1).
Use "Phone handle" icon in IDE to start listening for debug connections (e.g. as described in here)
Launch your php code from anywhere -- XDebug will attempt to debug every incoming request.
Here is an hour long webinar about the subject.