andy@AndyMacBookPro:~$ php -v
PHP Warning: Xdebug MUST be loaded as a Zend extension in Unknown on line 0
PHP 5.4.30 (cli) (built: Jul 29 2014 23:43:29)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2014 Zend Technologies
编辑php.ini
sudo vim /private/php.ini
将：
extension=/usr/local/Cellar/php54-xdebug/2.2.5/xdebug.so
修改为：
zend_extension=/usr/local/Cellar/php54-xdebug/2.2.5/xdebug.so
然后我们再看下，就好了：
andy@AndyMacBookPro:/private/etc$ php -v
PHP 5.4.30 (cli) (built: Jul 29 2014 23:43:29)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2014 Zend Technologies
with Xdebug v2.2.5, Copyright (c) 2002-2014, by Derick Rethans
andy@AndyMacBookPro:/private/etc$
关于更多：http://blog.163.com/lgh_2002/blog/static/440175262010910103342213/
zend_extension加载php扩展时需用全路径，而extension加载时可以用相对extension_dir的路径。
以上就介绍了PHP Warning: Xdebug MUST be loaded as a Zend extension in Unknown on line 0，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。