Debugger showing Mixin's static field always as null

[MajedDH]

Dart version: Dart SDK version: 2.18.7 (stable) (Unknown timestamp) on "linux_x64" working on Ubuntu 22.04
Let's consider the following main.dart file:

import 'dart:async';

class A with B {}

mixin B {
  static DateTime? lastTick;
  static Timer? checkActiveTimer;

  void startTimer() {
    checkActiveTimer = Timer.periodic(Duration(seconds: 1), (timer) {
      lastTick = DateTime.now();
      print(lastTick); //break point here
    });
  }

   bool lastActiveIsNull() {
    return lastActive == null;
  }
}

Future<void> main(List<String> arguments) async {
  var a = A();
  a.startTimer();
}

1. I've ran this file using the command /usr/lib/dart/bin/dart --enable-vm-service:34213 main.dart and got into the devtools to debug it. When the execution pauses at the break point. the lastTick member is evaluated inside the debugger as null. It's being printed and used inside the code correctly but the debugger is evaluating it wrongly as null.
   If I asked the debugger to evaluate B.lastTick it'll view it's value correctly, or If I used lastActiveIsNull() it'll return false so only calling the member directly in the watches will show null including for example print(lastTick), evaluating it will print null but calling it actually from the code will print it. shouldn't the two of them evaluate and work as the same value?

2. If I tried to evaluate this or call any kind of member instance method from inside the function inside the timer it'll throw out optimized out which is ok. I understand why. But if we call instance method like lastActiveIsNull() it'll throw NoSuchMethodError: Class 'String' has no instance method 'lastActiveIsNull'. which is not as clear. shouldn't it show optimized out or similiar errors rather than the String related error?

[srawlins]

I believe this is a bug for Flutter DevTools, at https://github.com/flutter/devtools, is that right, @MajedDH ? Could you open this bug over there?

[bkonyi]

@srawlins we've got a fix up for review already here :)

[MajedDH]

Oh, then there is no need to move it. it's here already.

Thanks everyone for the fast fix, I didn't expect it to go on review that fast 😄 .

Should the issue be closed now?