flutter: ══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
flutter: The following assertion was thrown while handling a gesture:
flutter: 'package:flutter/src/cupertino/route.dart': Failed assertion: line 637 pos 12:
flutter: 'controller.isAnimating': is not true.
flutter:
flutter: Either the assertion indicates an error in the framework itself, or we should provide substantially
flutter: more information in this error message to help you determine and fix the underlying cause.
flutter: In either case, please report this assertion by filing a bug on GitHub:
flutter:   https://github.com/flutter/flutter/issues/new?template=BUG.md
flutter:
flutter: When the exception was thrown, this was the stack:
flutter: #2      _CupertinoBackGestureController.dragEnd (package:flutter/src/cupertino/route.dart:637:12)
flutter: #3      _CupertinoBackGestureDetectorState._handleDragEnd (package:flutter/src/cupertino/route.dart:507:28)
flutter: #4      DragGestureRecognizer.didStopTrackingLastPointer.<anonymous closure> (package:flutter/src/gestures/monodrag.dart:255:45)
flutter: #5      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:120:24)
flutter: #6      DragGestureRecognizer.didStopTrackingLastPointer (package:flutter/src/gestures/monodrag.dart:255:9)
flutter: #7      OneSequenceGestureRecognizer.stopTrackingPointer (package:flutter/src/gestures/recognizer.dart:249:9)
flutter: #8      OneSequenceGestureRecognizer.stopTrackingIfPointerNoLongerDown (package:flutter/src/gestures/recognizer.dart:258:7)
flutter: #9      DragGestureRecognizer.handleEvent (package:flutter/src/gestures/monodrag.dart:193:5)
flutter: #10     PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)
flutter: #11     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)
flutter: #12     _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:214:19)
flutter: #13     _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:192:22)
flutter: #14     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:149:7)
flutter: #15     _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:101:7)
flutter: #16     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:85:7)
flutter: #20     _invoke1 (dart:ui/hooks.dart:203:10)
flutter: #21     _dispatchPointerDataPacket (dart:ui/hooks.dart:138:5)
flutter: (elided 5 frames from class _AssertionError and package dart:async)
flutter:
flutter: Handler: onEnd
flutter: Recognizer:
flutter:   HorizontalDragGestureRecognizer#f7fde(debugOwner:
flutter:   _CupertinoBackGestureDetectorState<dynamic>#f1e2d, start behavior: down)
flutter: ════════════════════════════════════════════════════════════════════════════════════════════════════

Analyzing flutter_gallery...
No issues found! (ran in 5.7s)

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