Enable Xdebug in MAMP

Uncomment the zend_extension line and modify the /Applications/MAMP/bin/php/php5.x/conf/php.ini file to look like this:-

[xdebug]
zend_extension="/Applications/MAMP/bin/php/php5.4.10/lib/php/extensions/no-debug-non-zts-20100525/xdebug.so"
xdebug.remote_enable=1
xdebug.remote_host=localhost 

; On my machine, the default port 9000 has already been taken by something else.
xdebug.remote_port=9099 

; Recommended when using Symfony
xdebug.max_nesting_level=250

Then restart the servers in MAMP.

Refs

http://danpolant.com/want-to-run-xdebug-mamp-is-the-easiest-way/

http://xdebug.org/docs/all_settings