Reflectable is not a know builder

[yhhCh405]

Whenever I tried to build output with reflectableBuild, I always got this error:
ApplyBuilders: Configuring `reflectable:reflectable` in target but this is not a known Builder. Could anyone plz help me?

In pubspec.yaml

name: reflection
description: A new Flutter project
publish_to: "none"
version: 1.0.0+1

environment:
  sdk: ">=2.19.0 <3.0.0"
dependencies:
  cupertino_icons: ^1.0.2
  flutter:
    sdk: flutter
  reflectable: ^4.0.4

dev_dependencies:
  flutter_lints: ^2.0.0
  flutter_test:
    sdk: flutter
  build_runner: 
flutter:
  uses-material-design: true

In build.yaml

targets:
  $default:
    builders:
      reflectable:
        generate_for: 
          - bin/something.dart
        options:
          formatted: true

In bin/builder.dart

import 'package:reflectable/reflectable_builder.dart';

Future<void> main(List<String> args) async {
  await reflectableBuild(args);
}

In bin/something.dart

import 'package:reflectable/reflectable.dart';

import 'something.reflectable.dart';

void main() {
  initializeReflectable();
  ClassMirror cm = reflector.reflectType(TargetClass) as ClassMirror;
  print(cm.declarations);
}

const reflector = Reflector();

class Reflector extends Reflectable {
  const Reflector() : super(reflectedTypeCapability);
}

@reflector
class TargetClass {
  String name = "foo";
  void someMethod() {}
}

Then I run with this command: dart bin/builder.dart bin/something.dart

I got this output. But there is no expected print result.

[WARNING] ApplyBuilders: Configuring `reflectable:reflectable` in target `reflection:reflection` but this is not a known Builder
[INFO] BuildDefinition: Initializing inputs
[INFO] BuildDefinition: Reading cached asset graph...
[INFO] BuildDefinition: Reading cached asset graph completed, took 27ms

[INFO] BuildDefinition: Checking for updates since last build...
[INFO] BuildDefinition: Checking for updates since last build completed, took 276ms

[INFO] Build: Running build...
[INFO] Build: Running build completed, took 4ms

[INFO] Build: Caching finalized dependency graph...
[INFO] Build: Caching finalized dependency graph completed, took 17ms

[INFO] Build: Succeeded after 25ms with 0 outputs (0 actions)

[eernstg]

Hi @yhhCh405, I'd recommend that you do a few things differently, in order to follow the normal usage: You should not need bin/builder.dart at all, and the command used to perform the reflectable code generation step should be

> flutter pub run build_runner build bin

(Actually, the package does not seem to depend on anything in Flutter, so it could be turned into a plain Dart package and use dart pub run build_runner build bin).