Doctrine 2 gives 500 Error on simple query - symfony

Question

I have this doctrine query:
$attributeQuery = $em->createQuery("SELECT PARTIAL p.{id} FROM m:Product p JOIN m:BtgNode n WITH n.attribute = p.amazonCatUs1 WHERE n.id = :node")->setMaxResults(5);
$attributeQuery->setParameter('node', $amazonCategoryId);
$products = $attributeQuery->getResult();
Which causes a 500 error. When I comment out the getResult line, the page finishes loading, and when I run $attributeQuery->getSql() and execute the result though phpmyadmin the result return correctly in less than 0.001 seconds.
I cannot find anything at all to explain this behavior.
The full script:
$em = $app['orm.em'];
echo ini_get('memory_limit').'<br>';
ini_set('xdebug.var_display_max_depth', -1);
ini_set('xdebug.var_display_max_data', -1);
$productQuery = $em->createQuery("SELECT p FROM m:Product p WHERE p.amazonUsBrowse1 = :node OR p.amazonUsBrowse2 = :node");
$productQuery->setParameter('node', $amazonCategoryId);
$productQuery->useQueryCache(false);
//if results, then not clothing and simple, else complicated
$products = $productQuery->getResult();
print memory_get_usage(true);
if (count($products) == 0) {
$em->clear();
echo 'complex';
$attributeQuery = $em->createQuery("SELECT PARTIAL p.{id} FROM m:Product p JOIN m:BtgNode n WITH n.attribute = p.amazonCatUs1 WHERE n.id = :node")->setMaxResults(5);
$attributeQuery->setParameter('node', $amazonCategoryId);
//$attributeQuery->useQueryCache(false);
var_dump($attributeQuery->getSql());
$products = $attributeQuery->getResult();
var_dump($attributeQuery->getSql());
}
var_dump($products);
die();