Install Completes but Site not Available

Install completed successfully but http://localhost/gibbon/ produces a blank screen. Other webapps such as joomla and Adminer work fine.
During install of the standard Gibbon download I selected testing of new features to be OFF.

“Congratulations, your installation is complete. Feel free to go to your Gibbon homepage and login with the username and password you created.”

—INFO

[user@tower gibbon]$ mysql -V
mysql Ver 15.1 Distrib 10.0.13-MariaDB, for Linux (x86_64) using readline 5.1

[user@tower gibbon]$ uname -a
Linux tower 3.16.1-1-MANJARO #1 SMP PREEMPT Thu Aug 14 11:04:58 UTC 2014 x86_64 GNU/Linux

[user@tower gibbon]$ php -v
PHP 5.5.16 (cli) (built: Aug 21 2014 18:34:24)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
with Zend OPcache v7.0.4-dev, Copyright (c) 1999-2014, by Zend Technologies
with Suhosin v0.9.36, Copyright (c) 2007-2014, by SektionEins GmbH

Full php info here: http://codepad.org/g7ydXeFm

Thanks for letting us know about this problem. Have you got PHP set to show error messages on screen? Please do this in php.ini, and then check for any on screen error messages.