Weird Zend Framework issue - include_once is looking in the wrong folder

I've spent a lot of time troubleshooting this myself but none of what I've read solves my issue so I'm hoping I get some help here.

So anyway, I have written a PHP script that provides various functions to connect with Google Calendar. When I run this script directly using some inline test code to call my functions, everything runs fine. However, when I call the function from other scripts using 'require_once' to include it I get the following errors:

Warning: include_once(Zend\Gdata\Calendar\Extension\EventQuery.php) [function.include-once]: failed to open stream: No such file or directory in C:\Users\Luke Franklin\Clients\Tiers For Tea\Development\TiersForTea.com v1.1\lib\Zend\Loader.php on line 134
Warning: include_once() [function.include]: Failed opening 'Zend\Gdata\Calendar\Extension\EventQuery.php' for inclusion (include_path='.;C:\xampp\php\PEAR;C:\Users\Luke Franklin\Clients\Tiers For Tea\Development\TiersForTea.com v1.1\lib;C:\xampp\htdocs\TiersForTea.com\lib') in C:\Users\Luke Franklin\Clients\Tiers For Tea\Development\TiersForTea.com v1.1\lib\Zend\Loader.php on line 134

Your first thoughts might be that I'm not using the correct include path, but I have checked and rechecked this many times. I even tried hard coding the path. I'm quite sure that I'm using the correct path.

Now for the weird bit. If you look at the error you will notice the file Zend is trying to include: Zend\Gdata\Calendar\Extension\EventQuery.php. This file does not actually exist in the 'Extension' folder. It does exist in the parent folder though. If I just copy 'EventQuery.php' into the 'Extension' folder my script runs as expected. Weird, right?

So that does sorta solve my problem, but I would like to know what's going on here in-case it creates further issues. I should also note that I'm calling this script into an OpenCart module.

You might want to see some of my code so here's a snippet of the important bits, if you want more details just let me know:

<?php
set_include_path(get_include_path() . PATH_SEPARATOR . realpath('\\lib') . PATH_SEPARATOR . "C:\\xampp\\htdocs\\TiersForTea.com\\lib");
require_once('Zend/Loader.php');

function connect() {
    Zend_Loader::loadClass('Zend_Gdata');
    Zend_Loader::loadClass('Zend_Gdata_ClientLogin');
    Zend_Loader::loadClass('Zend_Gdata_Calendar');

Solution

I doubt the error exists in any of the Zend files as you have indicated it works correctly in your isolation tests.

The error is thrown from Zend_Loader which means something in your code is making reference to Zend_Gdata_Calendar_Extension_EventQuery.

Check the stack trace for the error if available to pinpoint the location. If that's not available, do a global find for that string. If you find any matches, you will need to change them to Zend_Gdata_Calendar_EventQuery.

Update

Seems this is a known bug(s)

It's an issue when your code registers an error handler using ErrorException. Apparently it's fixed in the 1.12 branch but hasn't made it to a release yet.

There's a patch in the 11959 bug report that fixes the issue