Build failure on gatsby App because of object.assign not resolve in node_modules/assert

Working on Gatsby app and suddenly getting this issue, causing build fail:

Generating development JavaScript bundle failed

Can't resolve 'object.assign/polyfill' in 'C:\Home\ARK\Repos\shape-website-3\shape-website\website\node_modules\assert'

If you're trying to use a package make sure that 'object.assign/polyfill' is installed. If you're trying to use a local file make sure that the path is correct.

File: node_modules\assert\assert.js

Required urgent attention, please!

Gatsby の development-bundle の失敗を再現し、node_modules/assert/assert.js を調査して、object.assign/polyfill への参照に注目してください。Gatsby のビルドで依存関係の解決動作を確認してください。報告されたモジュール不足エラーなしでバンドルが完了すれば完了です。

索引モデルが issue の本文から書いたものです。