PhpStorm built-in server: Debug incoming requests

I am (locally) hosting a PHP script with PhpStorms built-in Server. Is there a way to debug an incoming HTTP request?

I know that there is the “PHP HTTP Request” run-configuration, which allows you to perform a request and debug it, but somehow my problem only occurs when the requests is coming from an other application. I have no clue why.

Currently, I use the “PHP Built-in Web Server” run-configuration to host the script.

Thanks!

Answer

For me, following was the solution: Adding XDEBUG_SESSION_START=1 to the request parameters and listening to debugger connections in PhpStorm (I use xdebug).

Big thanks to @LazyOne for giving me the answer! His suggestion really helped.