v3.0.8 had unintended braking change to the CJS version where the require was an object that consisted of default and defaultNotifier so it had to be used like this:
whyDidYouRender.default(React) // unintended 3.0.8 use that has been fixed.
This is fixed in v3.0.9.
defaultNotifier is exported on the whyDidYouRender instead and the CJS library version can be used like this again:
whyDidYouRender(React);
const defaultNotifier = whyDidYouRender.defaultNotifier;