I don\'t know if there\'s any? but is php built in web server also save its error logs in a file? for tailing purposes, like when creating virtual host in apache.
UP
To update for Mac OS X High Sierra (10.13.5): this worked for me with no need to change any PHP defaults. Just use
error_log('*** notice this***');
and tail the error log:
tail -f /var/log/apache2/error_log