I'm sorry if it sounds like I'm being a dick; but I'm incredibly frustrated to have poured so much effort into trying to make Dart a viable option for a rewrite where I work (I've even been working on a Visual Studio extension since all the devs here are primitively .NET devs).
To find something so fundamental missing with no reasonable solution (and no information from the Dart team) is frustrating; it's not going to make selling Dart to my colleagues any easier.