Flutter attach only works when the main file is called 'lib/main.dart'

[DaveShuckerow]

$ cd path/to/flutter/examples/flutter_gallery
$ mv lib/main.dart lib/run.dart
$ flutter run lib/run.dart
<snip out waiting for the app to deploy and start.>
^C
$ flutter attach
<start the gallery app back up>
Your application could not be compiled, because its dependencies could not be established.
Could not read "path/to/flutter/examples/flutter_gallery/lib/main.dart" when determining Dart dependencies.

[DaveShuckerow]

The root cause is that the ResidentRunner we use to attach and do hot reloads with will try to find a main.dart file when a target isn't announced. Attach doesn't provide a target, so it uses the default behavior always.

[DaveShuckerow]

Suggestion from @jacob314:

https://github.com/dart-lang/sdk/blob/master/runtime/vm/service/service.md#isolate
Isolate.rootLib should give you a good idea what the root library was. Can we use it to handle this case better?

[jonahwilliams]

I think this has since been fixed? https://github.com/flutter/flutter/blob/master/packages/flutter_tools/lib/src/commands/attach.dart#L267

Tentatively closing.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.