Just saw this… Sad to see you go, @tromey! I hope you won’t disappear altogether.
I maintain a VSCode debugger extension, which is at least partially Rust-focused. In fact, it’s based on rust-lldb (the customized lldb fork, not the shell script) at the moment, so losing it would be very sad indeed 
. I hope @nikomatsakis has picked it only as an example.
I also did some work around rustc’s debug info emission parts a few years back. If there will be a debugging WG, I think I’d like to participate in some capacity.