I’ve recently had to set up XDebug with MAMP Pro on OS X and it’s a little unintuitive. The instructions over at MacGDBp helped me tremendously, and they’ve made a nice debugger.
The latest version of MAMP/MAMP Pro comes with the XDebug binary already bundled. The unintuitive part is that you’ll need to edit your MAMP Pro php.ini file to point to the xdebug.so file in the MAMP folder. While MAMP Pro is open, go to File -> Edit Template -> PHP -> (PHP Version you use), and add the following lines to your php.ini.
; XDebug zend_extension="/Applications/MAMP/bin/php/php5.3.6/lib/php/extensions/no-debug-non-zts-20090626/xdebug.so" xdebug.remote_enable=1 xdebug.remote_host=localhost xdebug.remote_port=9000 xdebug.remote_autostart=1