php does not seem to be setup properly to query system environment variables. The test with getenv("PATH") only returns an empty response.

To fix this error edit php5-fpm config file

sudo vi /etc/php5/fpm/pool.d/www.conf

uncomment the following line


env[PATH] = /usr/local/bin:/usr/bin:/bin

and restart php5-fpm

sudo service php5-fpm restart