As you probably know, Dart recently hit M1. I'm currently trying to keep up with the rapid fire changes that are coming in from the Dart team to keep DartBox2D an accurate representation of state-of-the-art Dart.
If you see anything break, firstly, I apologise. Secondly, please either submit a fix (yay) or just let me know (yay-ish).
Thanks!
PS - we're also on pub now, which is nice.