This is a special case but we may run in to other cases before upgrading to webpack v3. In webpack v1 many plugins and loaders used top-level configuration keys to handle custom configuration. webpack-validator does not like this, but it does provide the option to whitelist keys, which is exactly what I did here. I also added a (hopefully) helpful error message to clarify what went wrong in the case of an invalid webpack config.
This is definitely late, but on behalf of the entire Gatsby community, I wanted to say thank you for being here.
Gatsby is built by awesome people like you. Let us say “thanks” in two ways:
If you have questions, please don’t hesitate to reach out to us: tweet at @gatsbyjs and we’ll come a-runnin’.