While trying to track down some leaking processes on Dart-Code's integration tests, I noticed a lot of DevTools instances being spawned unexpectedly.

I can reproduce from the terminal on stable and latest master.

flutter create foo
cd foo
flutter run --machine -d flutter_tester --no-devtools

In another terminal, run

ps -x | grep devtools

In the output, there will be a DevTools instance running:

 2283 ttys001    0:00.26 /Users/danny/Dev/Google/flutter/bin/cache/dart-sdk/bin/dart devtools --no-launch-browser

I'm not yet sure why the processes aren't being cleaned up during my test run (it might be that we're aggressively terminating the DAP instead of gracefully shutting it down) and I'm looking into that, but it seems like these DevTools instances shouldn't be spawned at all.