Execute the following commands in your terminal.
Download Xdebug – you will need to follow alternate instructions if you don’t have PHP5 working on your machine already.
sudo apt-get install php5-xdebug
The package should modify your INI file for you, but just in case you need to edit it yourself open it up and make the following modification – on Ubuntu its typically at /etc/php5/apache2/php.ini – add the following line.
zend_extension="/usr/lib/php5/20110331/xdebug.so"
That path might be a little different on your system – just make sure its a fully qualified path to the xdebug.so file on your machine. Also remember to comment out any references to the Zend Debugger – you can’t run both at the same time.
Now restart Apache.
sudo /etc/init.d/apache2 restart
You may also need want enable html_errors. Search for html_errors in /etc/php5/apache2/php.ini and make sure it is set to On. A restart of Apache is also required.
html_errors = On
Double-check with phpinfo() to make sure that everything is installed properly – you may also want to set configurations for Xdebug in your php.ini file.