@a03pl Hi John,
The author for this book is not on DevTalk, but I checked in with him, and unfortunately, he has moved on to other things and is not able to offer help and support for the book anymore. Perhaps some kind soul here on Devtalk who has some #ruby experience would be willing to help? Apologies for not being able to give you a solution.
Best wishes,
Margaret
The Pragmatic Bookshelf