#33149 of dartSDK

a,dart

// in lib folder
import 'b.dart';

class A {
  final B b;

  A(this.b);
}

b.dart

// in lib folder
class B {}

c.dart

// in lib folder
import 'a.dart';
import 'package:test_bug/b.dart';

class C {
  final A a = A(B()); //error at this line.
}

main.dart

// in bin folder
void main() {}