Sometimes when you run a flutter command there is additional output printed to stdout, such as:

• downloading the Dart SDK
• downloading other components
• waiting for another Flutter process to release startup lock

There are some commands that use stdout for communication, such as flutter run --machine, flutter test --machine, flutter debug-adapter and this violates their protocols. For the first two, client editors just know to handle non-JSON output too, however for flutter debug-adapter the output must conform to the debug adapter protocol because it will be used by standard DAP clients that can't make exceptions.

I think some of this output comes from Dart code so the debug-adapter command could perhaps opt-out of it, but I think some also comes from the shell scripts (eg. downloading the Dart SDK) so doing it based on the command might be a little trickier (for ex. require parsing the command in the shell scripts).

@christopherfujino do you have any thoughts/opinions on the best way to do this?