"activity?.isScrolling is not true" exception with CupertinoScrollbar #70105
Description
In Chrome, dragging a Scrollbar widget prints an exception.
Steps to Reproduce
- Drag a scrollbar using the mouse by hovering and dragging over the scrollbar in Chrome
- Scroll with the scroll wheel (I am using an Apple magic mouse, so this is easy to do accidentally
- Observe the console prints "activity?.isScrolling is not true"
Logs
════════ Exception caught by gesture ═══════════════════════════════════════════════════════════════
Assertion failed: file:///Users/ryjohn/code/github/flutter/flutter/packages/flutter/lib/src/widgets/scroll_position_with_single_context.dart:80:12
activity!.isScrolling
is not true
Running "flutter pub get" in web_books... 358ms
Analyzing web_books...
No issues found! (ran in 1.7s)
[✓] Flutter (Channel dev, 1.24.0-7.0.pre, on Mac OS X 10.15.7 19H2 darwin-x64, locale en)
• Flutter version 1.24.0-7.0.pre at /Users/ryjohn/code/github/flutter/flutter
• Framework revision a0860f6e87 (11 days ago), 2020-10-29 20:07:34 -0700
• Engine revision 073263e39d
• Dart version 2.11.0 (build 2.11.0-260.0.dev)
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
• Android SDK at /Users/ryjohn/Library/Android/sdk
• Platform android-29, build-tools 29.0.3
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
• All Android licenses accepted.
[✓] Xcode - develop for iOS and macOS (Xcode 12.0.1)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 12.0.1, Build version 12A7300
• CocoaPods version 1.9.3
[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Android Studio (version 4.0)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 43.0.2
• Dart plugin version 192.7761
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
[✓] IntelliJ IDEA Ultimate Edition (version 2020.2.1)
• IntelliJ at /Applications/IntelliJ IDEA.app
• Flutter plugin version 50.0
• Dart plugin version 202.7206
[✓] VS Code (version 1.50.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.15.0
[✓] Connected device (3 available)
• iPhone 11 (mobile) • 91CA064B-6EA1-4AE6-93AA-10A35B5F06CE • ios • com.apple.CoreSimulator.SimRuntime.iOS-14-0 (simulator)
• Web Server (web) • web-server • web-javascript • Flutter Tools
• Chrome (web) • chrome • web-javascript • Google Chrome 86.0.4240.183
• No issues found!