There appears to be a file permission problem involving the /tmp/ directory which has caused my submissions for the Bob exercise to fail erroneously. I spoke with ety5297 about it and he claims that all tests pass successfully via his account, as they also do locally on my dev machine. Hopefully you can look into the situation and correct whatever has malfunctioned.
Thanks for creating an excellent product. I’m really enjoying the lessons and exercises, and learning loads. It’s quickly become part of my daily routine and will likely remain so.