lit: Uncaught (in promise) TypeError: Cannot read property 'nextSibling' of null

I’ve got a LitElement with render method:

render({restaurantId}) {
  const restaurantView = restaurant => html`
    <restaurant-view restaurant="${restaurant}">
      ${fetchReviews(restaurantId).then(reviewsList)}
    </restaurant-view>
  `;

  const restaurantList = restaurants => html`
    <restaurant-list restaurants="${restaurants}"></restaurant-list>
  `;

  const restaurant = fetchRestaurantById(restaurantId).then(restaurantView);
  const restaurants = fetchRestaurants().then(restaurantList);

  return restaurantId
    ? html`${until(restaurant, restaurantView())}`
    : html`${until(restaurants, restaurantList([]))}`;
}

When I load up a restaurantId, I get the following error:

lit-html.ts:776 Uncaught (in promise) TypeError: Cannot read property 'nextSibling' of null
    at removeNodes (lit-html.ts:776)
    at NodePart.clear (lit-html.ts:665)
    at NodePart._setNode (lit-html.ts:563)
    at NodePart._setTemplateResult (lit-html.ts:592)
    at NodePart.setValue (lit-html.ts:542)
    at value.then (lit-html.ts:659)
removeNodes @ lit-html.ts:776
clear @ lit-html.ts:665
_setNode @ lit-html.ts:563
_setTemplateResult @ lit-html.ts:592
setValue @ lit-html.ts:542
value.then @ lit-html.ts:659
Promise.then (async)
_setPromise @ lit-html.ts:657
setValue @ lit-html.ts:548
directive @ until.ts:23
getValue @ lit-html.ts:405
setValue @ lit-html.ts:530
update @ lit-html.ts:710
render @ lit-html.ts:177
_propertiesChanged @ lit-element.js:113
_flushProperties @ properties-changed.js:307
ready @ properties-changed.js:151
ready @ lit-element.js:79
_enableProperties @ properties-changed.js:287
connectedCallback @ properties-mixin.js:176
(anonymous) @ restaurant-reviews.js:117
Show 2 more blackboxed frames

Immediately after this exception, my view renders properly. Attempts to track down bugs in my own code that could cause this have so far turned up nothing. Perhaps consider a more verbose exception.

Thanks for considering this issue