Scrollbar Exception caught by scheduler library

This issue is related to declarative navigation 2 and Navigator.pages.
If I request a page by URL and that page has another page underneath which contains Scrollbar this error happens:

======== Exception caught by scheduler library =====================================================
The following TypeErrorImpl was thrown during a scheduler callback:
Unexpected null value.

When the exception was thrown, this was the stack: 
dart:sdk_internal 5041:11                                          throw_
dart:sdk_internal 5366:30                                          nullCheck
../packages/flutter/src/widgets/scroll_metrics.dart.lib.js 98:19   get maxScrollExtent
../packages/flutter/src/widgets/scrollbar.dart.lib.js 1304:34      [_handleScrollNotification]
../packages/flutter/src/widgets/widget_span.dart.lib.js 42486:59   [_dispatch]
...

My project is open source:
This is pages: https://github.com/aliyazdi75/gallery/blob/main/lib/presentation/screens/gallery/router.dart#L38
This is Scrollbar: https://github.com/aliyazdi75/gallery/blob/main/lib/presentation/screens/album/view/media/view/media.dart#L103

If I open the application by this URL: /gallery/album/album2?view=photo8
navigator.pages contains two pages: AlbumPage which has the Scrollbar and MediaFullscreenPage which is the front page.

Summary: If we open the application in a declarative way by the browser and it has a page underneath that contains Scrollbar this problem triggers.

@aliyazdi75

Hi @aliyazdi75
To better address the issue, Can you please provide your flutter doctor -v and flutter run --verbose logs, and a minimal complete reproducible code sample? instead of a project
Thank you

@TahaTesser

Hi @TahaTesser
Implementing Navigation 2 it's not minimal at all 😄 , but I did my best to reproduce this issue.
1- git clone [email protected]:5be066aa964b799fca66eebabec88c5f.git in a null-safety flutter project. Hosted here and scrollbar is here
2- flutter run -d chrome --verbose
3- Copy and paste to the end of the base and go to this URL: /book/0
4- Exception:

======== Exception caught by scheduler library =====================================================
The following TypeErrorImpl was thrown during a scheduler callback:
Unexpected null value.

When the exception was thrown, this was the stack: 
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 236:49      throw_
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 518:63  nullCheck
packages/flutter/src/widgets/scroll_metrics.dart 150:49                           get maxScrollExtent
packages/flutter/src/widgets/scrollbar.dart 1099:16                               [_handleScrollNotification]
packages/flutter/src/widgets/notification_listener.dart 206:27                    [_dispatch]
...
====================================================================================================

--verbose output

[  +74 ms] executing: uname -m
[  +32 ms] Exit code 0 from: uname -m
[        ] x86_64
[  +17 ms] executing: [/home/aliyazdi75/snap/flutter/common/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[   +6 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[        ] 05ce6ce51153dd92d68092091a465170584d842f
[        ] executing: [/home/aliyazdi75/snap/flutter/common/flutter/] git tag --points-at 05ce6ce51153dd92d68092091a465170584d842f
[  +13 ms] Exit code 0 from: git tag --points-at 05ce6ce51153dd92d68092091a465170584d842f
[   +1 ms] executing: [/home/aliyazdi75/snap/flutter/common/flutter/] git describe --match *.*.* --long --tags 05ce6ce51153dd92d68092091a465170584d842f
[  +32 ms] Exit code 0 from: git describe --match *.*.* --long --tags 05ce6ce51153dd92d68092091a465170584d842f
[        ] 2.1.0-10.0.pre-86-g05ce6ce511
[  +47 ms] executing: [/home/aliyazdi75/snap/flutter/common/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[   +5 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[        ] origin/master
[        ] executing: [/home/aliyazdi75/snap/flutter/common/flutter/] git ls-remote --get-url origin
[   +5 ms] Exit code 0 from: git ls-remote --get-url origin
[        ] https://github.com/flutter/flutter.git
[  +49 ms] executing: [/home/aliyazdi75/snap/flutter/common/flutter/] git rev-parse --abbrev-ref HEAD
[   +6 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[        ] master
[  +63 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[   +2 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[  +73 ms] executing: /home/aliyazdi75/Android/Sdk/platform-tools/adb devices -l
[  +48 ms] List of devices attached
[   +6 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[   +3 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[  +76 ms] Skipping pub get: version match.
[ +133 ms] Generating /home/aliyazdi75/Documents/AndroidStudioProjects/flutter_app/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java
[ +185 ms] Launching lib/main.dart on Chrome in debug mode...
[ +140 ms] Updating assets
[ +120 ms] Waiting for connection from debug service on Chrome...
[  +90 ms] <- reset
[   +6 ms] /home/aliyazdi75/snap/flutter/common/flutter/bin/cache/dart-sdk/bin/dart --disable-dart-dev /home/aliyazdi75/snap/flutter/common/flutter/bin/cache/artifacts/engine/linux-x64/frontend_server.dart.snapshot --sdk-root
/home/aliyazdi75/snap/flutter/common/flutter/bin/cache/flutter_web_sdk/ --incremental --target=dartdevc --debugger-module-names --experimental-emit-debug-metadata -DFLUTTER_WEB_AUTO_DETECT=true --output-dill
/tmp/flutter_tools.DRTAMU/flutter_tool.GBYQWZ/app.dill --libraries-spec file:///home/aliyazdi75/snap/flutter/common/flutter/bin/cache/flutter_web_sdk/libraries.json --packages
/home/aliyazdi75/Documents/AndroidStudioProjects/flutter_app/.dart_tool/package_config.json -Ddart.vm.profile=false -Ddart.vm.product=false --enable-asserts --track-widget-creation --filesystem-root
/tmp/flutter_tools.DRTAMU/flutter_tools.NSVIHJ --filesystem-scheme org-dartlang-app --initialize-from-dill build/b1b715402d823b7fd5c2b68d2edcb2ce.cache.dill.track.dill --platform
file:///home/aliyazdi75/snap/flutter/common/flutter/bin/cache/flutter_web_sdk/kernel/flutter_ddc_sdk_sound.dill --sound-null-safety
[  +28 ms] <- compile org-dartlang-app:/web_entrypoint.dart
[+24839 ms] Waiting for connection from debug service on Chrome... (completed in 24.9s)
[   +1 ms] Synced 29.1MB.
[  +20 ms] <- accept
[        ] Caching compiled dill
[ +293 ms] Using Google Chrome 89.0.4389.82 

[ +435 ms] [CHROME]:
[        ] [CHROME]:DevTools listening on ws://127.0.0.1:44903/devtools/browser/8940119f-4b8a-4863-86e1-fcd79cc4f87e
[ +641 ms] DwdsInjector: Received request for entrypoint at http://localhost:45071/main_module.bootstrap.js
[  +38 ms] MetadataProvider: Loading debug metadata...
[  +52 ms] MetadataProvider: Loaded debug metadata (sound null safety)
[  +13 ms] DwdsInjector: Injected debugging metadata for entrypoint at http://localhost:45071/main_module.bootstrap.js
[+3475 ms] ChromeProxyService: Initializing expression compiler for main_module.bootstrap.js with sound null safety: true
[ +791 ms] DevHandler: Debug service listening on ws://127.0.0.1:45815/2Hwa9akqGmo=/ws

[  +12 ms] Debug service listening on ws://127.0.0.1:45815/2Hwa9akqGmo=/ws
[        ] 💪 Running with sound null safety 💪
[   +5 ms] 🔥  To hot restart changes while running, press "r" or "R".
[        ] For a more detailed help message, press "h". To quit, press "q".
[+97428 ms] DwdsInjector: Received request for entrypoint at http://localhost:45071/main_module.bootstrap.js
[        ] MetadataProvider: Loading debug metadata...
[   +9 ms] MetadataProvider: Loaded debug metadata (sound null safety)
[   +5 ms] DwdsInjector: Injected debugging metadata for entrypoint at http://localhost:45071/main_module.bootstrap.js
[+2267 ms] ChromeProxyService: Initializing expression compiler for main_module.bootstrap.js with sound null safety: true
[+3174 ms] ══╡ EXCEPTION CAUGHT BY SCHEDULER LIBRARY ╞═════════════════════════════════════════════════════════
[  +23 ms] The following TypeErrorImpl was thrown during a scheduler callback:
[        ] Unexpected null value.
[        ] When the exception was thrown, this was the stack:
[        ] dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 236:49      throw_
[        ] dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 518:63  nullCheck
[        ] packages/flutter/src/widgets/scroll_metrics.dart 150:49                           get maxScrollExtent
[        ] packages/flutter/src/widgets/scrollbar.dart 1099:16                               [_handleScrollNotification]
[        ] packages/flutter/src/widgets/notification_listener.dart 206:27                    [_dispatch]
[  +19 ms] packages/flutter/src/widgets/notification_listener.dart 122:19                    visitAncestor
[   +4 ms] packages/flutter/src/widgets/scroll_notification.dart 31:18                       visitAncestor
[        ] packages/flutter/src/widgets/framework.dart 4037:39                               visitAncestorElements
[        ] packages/flutter/src/widgets/notification_listener.dart 138:13                    dispatch
[        ] packages/flutter/src/widgets/scroll_activity.dart 94:90                           dispatchScrollUpdateNotification
[        ] packages/flutter/src/widgets/scroll_position.dart 870:5                           didUpdateScrollPositionBy
[        ] packages/flutter/src/widgets/scrollbar.dart 908:25                                <fn>
[   +9 ms] packages/flutter/src/scheduler/binding.dart 1144:15                               [_invokeFrameCallback]
[   +5 ms] packages/flutter/src/scheduler/binding.dart 1090:9                                handleDrawFrame
[        ] packages/flutter/src/scheduler/binding.dart 865:7                                 <fn>
[        ] dart-sdk/lib/_internal/js_dev_runtime/private/isolate_helper.dart 48:19           internalCallback
[        ] ════════════════════════════════════════════════════════════════════════════════════════════════════

flutter doctor -v output

[✓] Flutter (Channel master, 2.1.0-11.0.pre.86, on Linux, locale en_US.UTF-8)
    • Flutter version 2.1.0-11.0.pre.86 at /home/aliyazdi75/snap/flutter/common/flutter
    • Framework revision 05ce6ce511 (6 days ago), 2021-03-03 11:04:02 -0800
    • Engine revision cd0e54348b
    • Dart version 2.13.0 (build 2.13.0-93.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /home/aliyazdi75/Android/Sdk
    • Platform android-30, build-tools 30.0.3
    • Java binary at: /home/aliyazdi75/Application/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • Chrome at google-chrome

[✓] Linux toolchain - develop for Linux desktop
    • clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
    • cmake version 3.10.2
    • ninja version 1.8.2
    • pkg-config version 0.29.1

[✓] Android Studio (version 4.1)
    • Android Studio at /home/aliyazdi75/Application/android-studio
    • Flutter plugin version 54.0.1
    • Dart plugin version 201.9335
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)

[✓] Connected device (2 available)
    • Linux (desktop) • linux  • linux-x64      • Linux
    • Chrome (web)    • chrome • web-javascript • Google Chrome 89.0.4389.82

• No issues found!

@aliyazdi75

Hi @aliyazdi75
Thanks for the code sample, I can reproduce the issue. No exception without scrollbar

code sample

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

void main() {
  runApp(BooksApp());
}

class Book {
  final String title;
  final String author;

  Book(this.title, this.author);
}

class BooksApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _BooksAppState();
}

class _BooksAppState extends State<BooksApp> {
  BookRouterDelegate _routerDelegate = BookRouterDelegate();
  BookRouteInformationParser _routeInformationParser =
      BookRouteInformationParser();

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      title: 'Books App',
      routerDelegate: _routerDelegate,
      routeInformationParser: _routeInformationParser,
    );
  }
}

class BookRouteInformationParser extends RouteInformationParser<BookRoutePath> {
  @override
  Future<BookRoutePath> parseRouteInformation(
      RouteInformation routeInformation) {
    final uri = Uri.parse(routeInformation.location!);
    // Handle '/'
    if (uri.pathSegments.length == 0) {
      return SynchronousFuture(BookRoutePath.home());
    }

    // Handle '/book/:id'
    if (uri.pathSegments.length == 2) {
      if (uri.pathSegments[0] != 'book')
        return SynchronousFuture(BookRoutePath.unknown());
      var remaining = uri.pathSegments[1];
      var id = int.tryParse(remaining);
      if (id == null) return SynchronousFuture(BookRoutePath.unknown());
      return SynchronousFuture(BookRoutePath.details(id));
    }

    // Handle unknown routes
    return SynchronousFuture(BookRoutePath.unknown());
  }

  @override
  RouteInformation? restoreRouteInformation(BookRoutePath path) {
    if (path.isUnknown) {
      return RouteInformation(location: '/404');
    }
    if (path.isHomePage) {
      return RouteInformation(location: '/');
    }
    if (path.isDetailsPage) {
      return RouteInformation(location: '/book/${path.id}');
    }
    return null;
  }
}

class BookRouterDelegate extends RouterDelegate<BookRoutePath>
    with ChangeNotifier, PopNavigatorRouterDelegateMixin<BookRoutePath> {
  final GlobalKey<NavigatorState> navigatorKey;

  Book? _selectedBook;
  bool show404 = false;

  List<Book> books = [
    Book('Stranger in a Strange Land', 'Robert A. Heinlein'),
    Book('Foundation', 'Isaac Asimov'),
    Book('Fahrenheit 451', 'Ray Bradbury'),
  ];

  BookRouterDelegate() : navigatorKey = GlobalKey<NavigatorState>();

  BookRoutePath get currentConfiguration {
    if (show404) {
      return BookRoutePath.unknown();
    }
    return _selectedBook == null
        ? BookRoutePath.home()
        : BookRoutePath.details(books.indexOf(_selectedBook!));
  }

  @override
  Widget build(BuildContext context) {
    return Navigator(
      key: navigatorKey,
      pages: [
        MaterialPage(
          key: ValueKey('BooksListPage'),
          child: BooksListScreen(
            books: books,
            onTapped: _handleBookTapped,
          ),
        ),
        if (show404)
          MaterialPage(key: ValueKey('UnknownPage'), child: UnknownScreen())
        else if (_selectedBook != null)
          BookDetailsPage(book: _selectedBook!)
      ],
      onPopPage: (route, result) {
        if (!route.didPop(result)) {
          return false;
        }

        // Update the list of pages by setting _selectedBook to null
        _selectedBook = null;
        show404 = false;
        notifyListeners();

        return true;
      },
    );
  }

  @override
  Future<void> setNewRoutePath(BookRoutePath path) {
    if (path.isUnknown) {
      _selectedBook = null;
      show404 = true;
      return SynchronousFuture<void>(null);
    }

    if (path.isDetailsPage) {
      if (path.id! < 0 || path.id! > books.length - 1) {
        show404 = true;
        return SynchronousFuture<void>(null);
      }

      _selectedBook = books[path.id!];
    } else {
      _selectedBook = null;
    }

    show404 = false;
    return SynchronousFuture<void>(null);
  }

  void _handleBookTapped(Book book) {
    _selectedBook = book;
    notifyListeners();
  }
}

class BookDetailsPage extends Page {
  final Book book;

  BookDetailsPage({
    required this.book,
  }) : super(key: ValueKey(book));

  Route createRoute(BuildContext context) {
    return MaterialPageRoute(
      settings: this,
      builder: (BuildContext context) {
        return BookDetailsScreen(book: book);
      },
    );
  }
}

class BookRoutePath {
  final int? id;
  final bool isUnknown;

  BookRoutePath.home()
      : id = null,
        isUnknown = false;

  BookRoutePath.details(this.id) : isUnknown = false;

  BookRoutePath.unknown()
      : id = null,
        isUnknown = true;

  bool get isHomePage => id == null;

  bool get isDetailsPage => id != null;
}

class BooksListScreen extends StatefulWidget {
  final List<Book> books;
  final ValueChanged<Book> onTapped;

  BooksListScreen({
    required this.books,
    required this.onTapped,
  });

  @override
  _BooksListScreenState createState() => _BooksListScreenState();
}

class _BooksListScreenState extends State<BooksListScreen> {
  late ScrollController _scrollController;

  @override
  void initState() {
    super.initState();
    _scrollController = ScrollController();
  }

  @override
  void dispose() {
    _scrollController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Scrollbar(
        controller: _scrollController,
        showTrackOnHover: true,
        isAlwaysShown: true,
        child: ListView(
          controller: _scrollController,
          children: widget.books
              .map<Widget>((book) => ListTile(
                    title: Text(book.title),
                    subtitle: Text(book.author),
                    onTap: () => widget.onTapped(book),
                  ))
              .toList(),
        ),
      ),
    );
  }
}

class BookDetailsScreen extends StatelessWidget {
  final Book book;

  BookDetailsScreen({
    required this.book,
  });

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Padding(
        padding: const EdgeInsets.all(8.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(book.title, style: Theme.of(context).textTheme.headline6),
            Text(book.author, style: Theme.of(context).textTheme.subtitle1),
          ],
        ),
      ),
    );
  }
}

class UnknownScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Center(
        child: Text('404!'),
      ),
    );
  }
}

logs

[  +35 ms] Running "flutter pub get" in stable_flutter... (completed in 1,082ms)
[ +107 ms] Generating
/home/taha/AndroidStudioProjects/stable_flutter/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegi
strant.java
[ +175 ms] Launching lib/main.dart on Chrome in debug mode...
[  +74 ms] Updating assets
[  +67 ms] Waiting for connection from debug service on Chrome...
[  +80 ms] <- reset
[   +8 ms] /home/taha/Code/flutter_stable/bin/cache/dart-sdk/bin/dart --disable-dart-dev
/home/taha/Code/flutter_stable/bin/cache/artifacts/engine/linux-x64/frontend_server.dart.snapshot --sdk-root
/home/taha/Code/flutter_stable/bin/cache/flutter_web_sdk/ --incremental --target=dartdevc
--debugger-module-names --experimental-emit-debug-metadata -DFLUTTER_WEB_AUTO_DETECT=true --output-dill
/tmp/flutter_tools.QTXJPZ/flutter_tool.SWLGNV/app.dill --libraries-spec
file:///home/taha/Code/flutter_stable/bin/cache/flutter_web_sdk/libraries.json --packages
/home/taha/AndroidStudioProjects/stable_flutter/.dart_tool/package_config.json -Ddart.vm.profile=false
-Ddart.vm.product=false --enable-asserts --track-widget-creation --filesystem-root
/tmp/flutter_tools.QTXJPZ/flutter_tools.GSBIYG --filesystem-scheme org-dartlang-app --initialize-from-dill
build/b1b715402d823b7fd5c2b68d2edcb2ce.cache.dill.track.dill --platform
file:///home/taha/Code/flutter_stable/bin/cache/flutter_web_sdk/kernel/flutter_ddc_sdk_sound.dill
--sound-null-safety
[   +8 ms] <- compile org-dartlang-app:/web_entrypoint.dart
[+12025 ms] Waiting for connection from debug service on Chrome... (completed in 12.1s)
[        ] Synced 28.9MB.
[        ] <- accept
[        ] Caching compiled dill
[ +133 ms] Using Chromium 89.0.4389.82 snap

[ +141 ms] [CHROME]:Gtk-Message: 13:18:20.250: Failed to load module "appmenu-gtk-module"
[  +58 ms] [CHROME]:
[        ] [CHROME]:DevTools listening on
ws://127.0.0.1:43383/devtools/browser/08e79b77-a62a-45c2-9156-6c02160cf4f7
[ +244 ms] DwdsInjector: Received request for entrypoint at http://localhost:42897/main_module.bootstrap.js
[   +3 ms] MetadataProvider: Loading debug metadata...
[  +12 ms] MetadataProvider: Loaded debug metadata
[   +9 ms] DwdsInjector: Injected debugging metadata for entrypoint at
http://localhost:42897/main_module.bootstrap.js
[+1677 ms] DevHandler: Debug service listening on ws://127.0.0.1:36585/NyCQP1URENI=/ws

[   +6 ms] Debug service listening on ws://127.0.0.1:36585/NyCQP1URENI=/ws
[        ] 💪 Running with sound null safety 💪
[   +1 ms] 🔥  To hot restart changes while running, press "r" or "R".
[        ] For a more detailed help message, press "h". To quit, press "q".
[+27325 ms] DwdsInjector: Received request for entrypoint at http://localhost:42897/main_module.bootstrap.js
[        ] MetadataProvider: Loading debug metadata...
[   +4 ms] MetadataProvider: Loaded debug metadata
[   +1 ms] DwdsInjector: Injected debugging metadata for entrypoint at
http://localhost:42897/main_module.bootstrap.js
[+3312 ms] ══╡ EXCEPTION CAUGHT BY SCHEDULER LIBRARY ╞═════════════════════════════════════════════════════════
[   +2 ms] The following TypeErrorImpl was thrown during a scheduler callback:
[        ] Unexpected null value.
[        ] When the exception was thrown, this was the stack:
[        ] dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 236:49      throw_
[        ] dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 518:63  nullCheck
[        ] packages/flutter/src/widgets/scroll_metrics.dart 150:49                           get maxScrollExtent
[        ] packages/flutter/src/widgets/scrollbar.dart 1053:16
[_handleScrollNotification]
[        ] packages/flutter/src/widgets/notification_listener.dart 206:27                    [_dispatch]
[        ] packages/flutter/src/widgets/notification_listener.dart 122:19                    visitAncestor
[        ] packages/flutter/src/widgets/scroll_notification.dart 31:18                       visitAncestor
[        ] packages/flutter/src/widgets/framework.dart 3966:39
visitAncestorElements
[        ] packages/flutter/src/widgets/notification_listener.dart 138:13                    dispatch
[        ] packages/flutter/src/widgets/scroll_activity.dart 94:90
           dispatchScrollUpdateNotification
[        ] packages/flutter/src/widgets/scroll_position.dart 870:5
didUpdateScrollPositionBy
[        ] packages/flutter/src/widgets/scrollbar.dart 862:25                                <fn>
[        ] packages/flutter/src/scheduler/binding.dart 1144:15
[_invokeFrameCallback]
[        ] packages/flutter/src/scheduler/binding.dart 1090:9                                handleDrawFrame
[        ] packages/flutter/src/scheduler/binding.dart 865:7                                 <fn>
[        ] dart-sdk/lib/_internal/js_dev_runtime/private/isolate_helper.dart 48:19           internalCallback
[        ] ════════════════════════════════════════════════════════════════════════════════════════════════════

flutter doctor -v

[✓] Flutter (Channel stable, 2.0.1, on Linux, locale en_CA.UTF-8)
    • Flutter version 2.0.1 at /home/taha/Code/flutter_stable
    • Framework revision c5a4b4029c (6 days ago), 2021-03-04 09:47:48 -0800
    • Engine revision 40441def69
    • Dart version 2.12.0

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /home/taha/Code/SDK
    • Platform android-30, build-tools 30.0.3
    • ANDROID_HOME = /home/taha/Code/SDK
    • Java binary at: /home/taha/Code/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • CHROME_EXECUTABLE = /snap/bin/chromium

[✓] Linux toolchain - develop for Linux desktop
    • Ubuntu clang version 11.0.0-2
    • cmake version 3.16.3
    • ninja version 1.10.0
    • pkg-config version 0.29.2

[!] Android Studio (not installed)
    • Android Studio not found; download from
      https://developer.android.com/studio/index.html
      (or visit https://flutter.dev/docs/get-started/install/linux#android-setup
      for detailed instructions).

[✓] VS Code (version 1.54.1)
    • VS Code at /usr/share/code
    • Flutter extension version 3.20.0

[✓] Connected device (2 available)
    • Linux (desktop) • linux  • linux-x64      • Linux
    • Chrome (web)    • chrome • web-javascript • Chromium 89.0.4389.82 snap

! Doctor found issues in 1 category.

[✓] Flutter (Channel master, 2.1.0-11.0.pre.179, on Linux, locale en_CA.UTF-8)
    • Flutter version 2.1.0-11.0.pre.179 at /home/taha/Code/flutter_master
    • Framework revision 07e04484ea (4 hours ago), 2021-03-09 20:10:05 -0800
    • Engine revision 7764b5c55f
    • Dart version 2.13.0 (build 2.13.0-116.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /home/taha/Code/SDK
    • Platform android-30, build-tools 30.0.3
    • ANDROID_HOME = /home/taha/Code/SDK
    • Java binary at: /home/taha/Code/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • CHROME_EXECUTABLE = /snap/bin/chromium

[✓] Linux toolchain - develop for Linux desktop
    • Ubuntu clang version 11.0.0-2
    • cmake version 3.16.3
    • ninja version 1.10.0
    • pkg-config version 0.29.2

[✓] Android Studio (version 4.1)
    • Android Studio at /home/taha/Code/android-studio
    • Flutter plugin version 54.0.1
    • Dart plugin version 201.9335
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.54.1)
    • VS Code at /usr/share/code
    • Flutter extension version 3.20.0

[✓] Connected device (2 available)
    • Linux (desktop) • linux  • linux-x64      • Linux
    • Chrome (web)    • chrome • web-javascript • Chromium 89.0.4389.82 snap

• No issues found!

Thank you

@TahaTesser

@TahaTesser I think adding nnbd tag is useful.

This issue is missing a priority label. Please set a priority label when adding the triaged-design label.

We think this is fixed, if it can still be reproduced, please file a new issue with an updated reproduction. Thank you!

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.

Navigation Menu

Repository navigation

Scrollbar Exception caught by scheduler library #77609

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Scrollbar Exception caught by scheduler library #77609

Description

Activity

TahaTesser commented on Mar 9, 2021

aliyazdi75 commented on Mar 9, 2021

TahaTesser commented on Mar 10, 2021

aliyazdi75 commented on Mar 11, 2021

flutter-triage-bot commented on Dec 5, 2024

Piinks commented on Dec 11, 2024

github-actions commented on Dec 25, 2024

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions