Why is debugging and troubleshooting in Magento so difficult? Because of error messages like this:
Notice: Undefined variable: rootNode in C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Eav\Model\Entity\Attribute\Source\Config.php on line 53
Trace:
#0 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Eav\Model\Entity\Attribute\Source\Config.php(53): mageCoreErrorHandler(8, ‘Undefined varia…’, ‘C:\Domains\exam…’, 53, Array)
#1 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Adminhtml\Block\Widget\Form.php(196): Mage_Eav_Model_Entity_Attribute_Source_Config->getAllOptions(true, true)
#2 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Adminhtml\Block\Customer\Edit\Tab\Account.php(54): Mage_Adminhtml_Block_Widget_Form->_setFieldset(Array, Object(Varien_Data_Form_Element_Fieldset))
#3 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Adminhtml\Block\Customer\Edit\Tabs.php(58): Mage_Adminhtml_Block_Customer_Edit_Tab_Account->initForm()
#4 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Abstract.php(642): Mage_Adminhtml_Block_Customer_Edit_Tabs->_beforeToHtml()
#5 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Text\List.php(43): Mage_Core_Block_Abstract->toHtml()
#6 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Abstract.php(643): Mage_Core_Block_Text_List->_toHtml()
#7 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Abstract.php(503): Mage_Core_Block_Abstract->toHtml()
#8 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Abstract.php(454): Mage_Core_Block_Abstract->_getChildHtml(‘left’, true)
#9 C:\Domains\example.com\wwwroot\magento\app\design\adminhtml\default\default\template\page.phtml(58): Mage_Core_Block_Abstract->getChildHtml(‘left’)
#10 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Template.php(144): include(‘C:\Domains\leoa…’)
#11 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Template.php(176): Mage_Core_Block_Template->fetchView(‘adminhtml\defau…’)
#12 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Template.php(193): Mage_Core_Block_Template->renderView()
#13 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Adminhtml\Block\Template.php(81): Mage_Core_Block_Template->_toHtml()
#14 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Block\Abstract.php(643): Mage_Adminhtml_Block_Template->_toHtml()
#15 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Model\Layout.php(526): Mage_Core_Block_Abstract->toHtml()
#16 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Controller\Varien\Action.php(347): Mage_Core_Model_Layout->getOutput()
#17 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Adminhtml\controllers\CustomerController.php(117): Mage_Core_Controller_Varien_Action->renderLayout()
#18 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Controller\Varien\Action.php(376): Mage_Adminhtml_CustomerController->editAction()
#19 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Controller\Varien\Router\Standard.php(248): Mage_Core_Controller_Varien_Action->dispatch(‘edit’)
#20 C:\Domains\example.com\wwwroot\magento\app\code\core\Mage\Core\Controller\Varien\Front.php(158): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#21 C:\Domains\example.com\wwwroot\magento\app\Mage.php(459): Mage_Core_Controller_Varien_Front->dispatch()
#22 C:\Domains\example.com\wwwroot\magento\index.php(65): Mage::run()
#23 {main}
Yes, it screams "undefined variable" which is rootNode but through Magento’s excellent use of object oriented spaghetti, the error does not in anyway reveal what is truly causing rootNode to be undefined nor where to even begin looking.