https://codesandbox.io/s/elastic-mayer-rzz4h2?file=/package.json

This is supposed to `console.error` but it doesn't.

17 warns: https://codesandbox.io/s/admiring-minsky-sze07m?file=/src/App.js
/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *