fix: improve logging when failing to get newly created user

Signed-off-by: Robin Appelman <robin@icewind.nl>

Author: icewind1991

lib/private/User/Manager.php

@@ -454,7 +454,16 @@ public function createUserFromBackend($uid, $password, UserInterface $backend):
 		if ($state === false) {
 			throw new \InvalidArgumentException($l->t('Could not create account'));
 		}
-		$user = $this->getUserObject($uid, $backend);
+		try {
+			$user = $this->getUserObject($uid, $backend);
+		} catch (\RuntimeException $e) {
+			$this->logger->error('Failed to get user after creation', [
+				'exception' => $e,
+				'uid' => $uid,
+				'exists_backend' => $backend->userExists($uid),
+			]);
+			throw new \RuntimeException('Failed to get user after creation', previous: $e);
+		}
 		if ($user instanceof IUser) {
 			/** @deprecated 21.0.0 use UserCreatedEvent event with the IEventDispatcher instead */
 			$this->emit('\OC\User', 'postCreateUser', [$user, $password]);