Once you have vagrant ssh-ed to your Homestead VM the first thing you need to do it download the latest compatible version of Xdebug (2.4.0RC3 at the time of writing) and build it:
cd /tmp
wget [http://xdebug.org/files/xdebug-2.4.0rc3.tgz](http://xdebug.org/files/xdebug-2.4.0rc3.tgz)
tar xvzf xdebug-2.4.0rc3.tgz
cd xdebug-2.4.0RC3/
phpize
./configure
make
sudo cp modules/xdebug.so /usr/lib/php/20151012/
You then need to the add your Xdebug config in /etc/php/mods-available/xdebug.ini:
; configuration for php xdebug module
; priority=20
zend\_extension=/usr/lib/php/20151012/xdebug.so xdebug.idekey="phpstorm"
xdebug.remote\_enable=1
xdebug.remote\_connect\_back=1
xdebug.remote\_port=9000
xdebug.max\_nesting\_level=300
xdebug.scream=0
xdebug.cli\_color=1
xdebug.show\_local\_vars=1
Finally you need to add some symlinks so your new config file will be read by PHP:
sudo ln -s /etc/php/mods-available/xdebug.ini /etc/php/7.0/fpm/conf.d/20-xdebug.inisudo ln -s /etc/php/mods-available/xdebug.ini /etc/php/7.0/cli/conf.d/20-xdebug.ini
Finally restart PHP-FPM and you should be good to go:
sudo service php7.0-fpm restart
Most of this was based on the helpful Xdebug installation wizard.