I'm seeing some weird behavior is a development system I upgraded from Magento CE 1.6 to Magento CE 1.8.1. Specifically, the site never gets page front controller dispatch due to the following error.
Fatal error: Call to a member function rewrite() on a non-object in /Users/alanstorm/Sites2013/magento-test-migration.dev/app/code/core/Mage/Core/Controller/Varien/Front.php on line 165
I traced this down to the following call failing to return an object.
$className = (string)Mage::getConfig()->getNode('global/request_rewrite/model');
For some reason, by global configuration does not have a
request_rewrite node, even though I've cleared my cache, and this code exists on disk.
I recalls seeing similar reports in the past year since the release of 188.8.131.52. Does anyone know why this happens?