I updated some npm packages in my Gatsby project and now I\'m seeing this warning in console:
React-hot-loader: react-
So this appears to be an artifact of the development process. Looks like there was some back-and-forth on what to do in this case. The error message was commented out, and then later added back as a fix for an issue: https://github.com/gaearon/react-hot-loader/commit/efc3d6b5a58df77f6e0d5ca21bef54e8f8732070.
So, it looks like it's a minor warning, and you may be just fine unless you need specific features.
It might be a good idea to ask for clarity on this from the maintainers, since they seem slightly confused themselves :)