<p dir="auto">This could be related to <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="238210164" data-permission-text="Title is private" data-url="https://github.com/flutter/flutter/issues/10934" data-hovercard-type="issue" data-hovercard-url="/flutter/flutter/issues/10934/hovercard" href="https://github.com/flutter/flutter/issues/10934">#10934</a> but I don't think so, so raising a new issue.</p>
<p dir="auto">I'm sending a hot reload with pause=true then when I get <code class="notranslate">PausePostRequest</code> I'm deleting and re-sending breakpoints (I also then send a resume, which fails, but I'm discarding the error for now - that's what <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="238210164" data-permission-text="Title is private" data-url="https://github.com/flutter/flutter/issues/10934" data-hovercard-type="issue" data-hovercard-url="/flutter/flutter/issues/10934/hovercard" href="https://github.com/flutter/flutter/issues/10934">#10934</a> is about).</p>
<p dir="auto">However, my breakpoints never appear to be hit after this has happened. I'm aware that <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="238210164" data-permission-text="Title is private" data-url="https://github.com/flutter/flutter/issues/10934" data-hovercard-type="issue" data-hovercard-url="/flutter/flutter/issues/10934/hovercard" href="https://github.com/flutter/flutter/issues/10934">#10934</a> means there's a race, however I'm doing this:</p>
<ul dir="auto">
<li>Hitting breakpoint in Stocks example app <code class="notranslate">theme</code> getter (<code class="notranslate">main.dart:66</code>)</li>
<li>Sending resume (twice, since this getter is called twice)</li>
<li>Changing the colour of one of the themes</li>
<li>Sending a hot reload - the colour correctly updates</li>
<li>Switching theme using the app's slide-out drawer</li>
</ul>
<p dir="auto">When switching theme, the theme updates on the screen but the debugger never breaks.</p>
<p dir="auto">It's harder to repro this in a script like I did for the other cases so I'm hoping this is enough info to go on; but if you really can't repro/understand this then I can try and find time to do this.</p>
<p dir="auto">Here's the log - I've included a trimmed version without all the stuff I think is not relevant but also the full log (best viewed without wrapping).</p>
<p dir="auto"><a href="https://github.com/flutter/flutter/files/1113229/observatory.trimmed.txt">observatory.trimmed.txt</a><br>
<a href="https://github.com/flutter/flutter/files/1113230/observatory.txt">observatory.txt</a></p>
<p dir="auto">The trivial app below is wrong because the build function is missing its BuildContext argument. I have made this mistake several times.</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="import 'package:flutter/material.dart';

class BadApp extends StatelessComponent {

  Widget build() {
    return new Text(&quot;FAIL&quot;);
  }
}

void main() {
  runApp(new MaterialApp(
    routes: {
      '/': (RouteArguments args) =&gt; new BadApp()
    }
  ));
}"><pre class="notranslate"><code class="notranslate">import 'package:flutter/material.dart';

class BadApp extends StatelessComponent {

  Widget build() {
    return new Text("FAIL");
  }
}

void main() {
  runApp(new MaterialApp(
    routes: {
      '/': (RouteArguments args) =&gt; new BadApp()
    }
  ));
}
</code></pre></div>
<p dir="auto">I assume that the analyzer would have warned me off running the app. Doing so yields 128 stack frames, only one of which comes from the app.  The failure mode is somewhat confusing, moreso in the context of a larger app.</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="android: --------- beginning of system
android: I/flutter : -- EXCEPTION CAUGHT BY WIDGETS LIBRARY ---------------------------------
android: I/flutter : Exception caught while building _ModalScopeStatus(active)
android: I/flutter : type '() =&gt; Widget' is not a subtype of type 'WidgetBuilder' of 'value'.
android: I/flutter : Stack trace:
android: I/flutter : #0      ComponentElement._builder= (packages/flutter/src/widgets/framework.dart:1136)
android: I/flutter : #1      StatelessComponentElement.StatelessComponentElement (packages/flutter/src/widgets/framework.dart:1206)
android: I/flutter : #2      StatelessComponent.createElement (packages/flutter/src/widgets/framework.dart:309)
...
android: I/flutter : #128    main (/builds/dev/flutter/examples/widgets/test.dart:15)"><pre class="notranslate"><code class="notranslate">android: --------- beginning of system
android: I/flutter : -- EXCEPTION CAUGHT BY WIDGETS LIBRARY ---------------------------------
android: I/flutter : Exception caught while building _ModalScopeStatus(active)
android: I/flutter : type '() =&gt; Widget' is not a subtype of type 'WidgetBuilder' of 'value'.
android: I/flutter : Stack trace:
android: I/flutter : #0      ComponentElement._builder= (packages/flutter/src/widgets/framework.dart:1136)
android: I/flutter : #1      StatelessComponentElement.StatelessComponentElement (packages/flutter/src/widgets/framework.dart:1206)
android: I/flutter : #2      StatelessComponent.createElement (packages/flutter/src/widgets/framework.dart:309)
...
android: I/flutter : #128    main (/builds/dev/flutter/examples/widgets/test.dart:15)
</code></pre></div>
<p dir="auto">I don't know if it would be worth doing something about this.</p>