Strage filename shown in php include error

Question

I'm getting the following error randomly:

PHP Warning: include_once(TestSystem.php) [function.include-once]: failed to open stream: No such file or directory in À«‘ on line 17

The file TestSystem.php exists and is included (most of the times, which makes this even weirder). The second issue is the reported file "À«‘" which should be "index.php". I've tried with include, include_once, require and require_once but I get the same behavior.

Anyone knows why this might happen? Thanks in advance.

Server version: Apache/2.2.24 (Unix) PHP 5.3.26 (cli) (built: Jul 7 2013 19:05:08) Copyright (c) 1997-2013 The PHP Group Zend Engine v2.3.0, Copyright (c) 1998-2013 Zend Technologies with Xdebug v2.2.3, Copyright (c) 2002-2013, by Derick Rethans

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Xdebug

Answer 1

Disabled xdebug and everything went back to normal.