Some Smart Display owners have been able to successfully bypass the bug by resetting their device through the Google Home app and setting it up again with all the settings left to their defaults. Others have had luck by simply letting the Smart Display work through the update for a couple of days. For the most part, there doesn't seem to be a workaround that's guaranteed to succeed.
According to an Lenovo employee who posted in the company's official support forums, Google has classified the issue as a "top priority" and is working on a fix. However, the employee didn't say when to expect the new update. "For the time being the only course of action is to wait for the team to roll out a fix," they added.
We've reached out to both Google and Lenovo for comment, as well to find out if they have a preliminary timeline to share. We'll update this article when we hear back. In the meantime, if your Smart Display is stuck in an update loop, Lenovo recommends you keep it plugged in. That way you'll get the bug fix as soon as it's available.
Update 10/1/19 3:49PM ET: A Google spokesperson told Engadget that the bug has been fixed and that it was caused by a server issue. No additional steps are required to receive the software update that will remedy the problem. If your device was unplugged, simply resume the setup process like you normally would.