PHP - Unable to find files inside of shutdown function

Question

I'm trying to set up some error logging

register_shutdown_function('shutdown');

but whenever I try to include a file inside of the shutdown function - it cannot be found, even though it exists and is included just fine throughout my application elsewhere

function shutdown()
{
    require_once LIB_DIR.'phpmailer/class.phpmailer.php';
}

Gives me an error saying the file could not be found.. am I missing something here, does the relative path to a file change inside the shutdown function or something?

Answer 1

One of your comments suggest you're using a relative path:

../web-app/app/libraries/phpmailer/class.phpmailer.php
^^

That's generally unreliable in the PHP universe but in this particular case:

Working directory of the script can change inside the shutdown function under some web servers, e.g. Apache.

If the error message doesn't display the full path, you can at least print current directory yourself for debugging purposes:

var_dump(getcwd());