When running composer diagnose, I get the following error :
composer diagnose
The xdebug extension is loaded, this can slow down Composer a little. Disablin
Here is my quick solution to get rid off the Xdebug warning on PHP5-cli version. I have removed the support of Xdebug for PHP5-cli on Ubuntu 14.04.
cd /etc/php5/cli/conf.d/ sudo rm 20-xdebug.ini
cd /etc/php5/cli/conf.d/
sudo rm 20-xdebug.ini
Now no more Xdebug warning on PHP5-cli.