Dart debugger calling methods untimely

Question

I'm debugging a Flutter/Dart app with IntelliJ and I have weird thing happenings: some methods are called but the debugger does not stop at breakpoints.

After having lost hours on that, I finally understood that the problem is caused by the debugger itself: to display values of variables, it calls methods by itself, causing odd behaviors. What can be done to prevent this?

/*
Output in Debug:

current: 1
current: 2
current: 3
current: 1
current: 2
current: 3
breakpoint here
current: 1
current: 2
current: 3
current: 1
current: 2
current: 3
current: 1
for: 1
current: 2
for: 2
current: 3
for: 3

Output in Run:

breakpoint here
current: 1
for: 1
current: 2
for: 2
current: 3
for: 3
*/
main() {
  var iterable = TestIterable();
  print('breakpoint here');
  for (var item in iterable) {
    print('for: $item');
  }
}

class TestIterable extends IterableBase {
  @override
  Iterator get iterator => TestIterator();
}

class TestIterator extends Iterator {
  int _index = 0;

  @override
  bool moveNext() => _index++ < 3;

  @override
  get current {
    print('current: $_index');
    return _index;
  }
}

Answer 1

Not specific to IDEA, I can see the same behavior in Dart Dev Tools : as soon as I try to inspect iterable variable, the code is run and value printed to console:

Not sure if this is expected, I'd suggest contacting Dart dev team by submitting an issue to https://github.com/dart-lang/sdk/issues