While trying to setup nginx + php-fpm (PHP with Fastcgi Process Manager) following this post from Homo-Adminus Blog, I got a vexing error: "No input file specified".

After searching through my system logs (an Arch Linux box), I found the following message in /var/log/everything.log:

Oct 18 18:08:27 engel php-cgi: PHP Warning: Unknown: open_basedir restriction in effect. File(/etc/nginx/html/hello.php) is not within the allowed path(s): (/home/:/tmp/:/usr/share/pear/) in Unknown on line 0

Once I changed the open_basedir in /etc/php/php.ini to the correct value, it worked flawlessly.

I hope this post can help to everybody who can find themselves in the same quest to get nginx+php-fpm setup to work.