background_locator: iOS 14+ crash on app startup when location set to 'Always Allow'

works. @mehdok you’re cool! thank you, you saved my project 😀

@johnvolkov Do you still have a problem with this?

Everything works fine for me, on all devices.

@mehdok my log: 2021-07-19 16:15:08.207538+0300 Runner[59446:6431906] [TSBackgroundFetch load]: ( ) 2021-07-19 16:15:08.207923+0300 Runner[59446:6431906] [TSBGAppRefreshSubscriber load]: { } 2021-07-19 16:15:08.673375+0300 Runner[59446:6431906] Metal API Validation Enabled 2021-07-19 16:15:09.054330+0300 Runner[59446:6431906] *** Assertion failure in -[FlutterEngine sendOnChannel:message:binaryReply:], FlutterEngine.mm:799 2021-07-19 16:15:09.075527+0300 Runner[59446:6431906] *** Terminating app due to uncaught exception ‘NSInternalInconsistencyException’, reason: ‘Sending a message before the FlutterEngine has been run.’ *** First throw call stack: ( 0 CoreFoundation 0x00007fff20422fba __exceptionPreprocess + 242 1 libobjc.A.dylib 0x00007fff20193ff5 objc_exception_throw + 48 2 CoreFoundation 0x00007fff20422de3 +[NSException raise:format:] + 0 3 Foundation 0x00007fff207748e7 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 191 4 Flutter 0x0000000100c5d006 -[FlutterEngine sendOnChannel:message:binaryReply:] + 544 5 background_locator 0x0000000100b05db0 -[BackgroundLocatorPlugin invokeMethod:arguments:] + 96 6 background_locator 0x0000000100b0780c -[DisposePluggable onServiceDispose] + 268 7 background_locator 0x0000000100b0751e -[BackgroundLocatorPlugin removeLocator] + 910 8 background_locator 0x0000000100b05fed -[BackgroundLocatorPlugin application:didFinishLaunchingWithOptions:] + 301 9 Flutter 0x0000000100c6aefd -[FlutterPluginAppLifeCycleDelegate application:didFinishLaunchingWithOptions:] + 296 10 Runner 0x00000001000d2ac2 $s6Runner11AppDelegateC11application_29didFinishLaunchingWithOptionsSbSo13UIApplicationC_SDySo0j6LaunchI3KeyaypGSgtF + 466 11 Runner 0x00000001000d2d03 $s6Runner11AppDelegateC11application_29didFinishLaunchingWithOptionsSbSo13UIApplicationC_SDySo0j6LaunchI3KeyaypGSgtFTo + 211 12 UIKitCore 0x00007fff246bd6f1 -[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:] + 232 13 UIKitCore 0x00007fff246bf33b -[UIApplication _callInitializationDelegatesWithActions:forCanvas:payload:fromOriginatingProcess:] + 4046 14 UIKitCore 0x00007fff246c4d63 -[UIApplication _runWithMainScene:transitionContext:completion:] + 1237 15 UIKitCore 0x00007fff23ce629b -[_UISceneLifecycleMultiplexer completeApplicationLaunchWithFBSScene:transitionContext:] + 122 16 UIKitCore 0x00007fff24272726 _UIScenePerformActionsWithLifecycleActionMask + 88 17 UIKitCore 0x00007fff23ce6dad __101-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]_block_invoke + 198 18 UIKitCore 0x00007fff23ce686e -[_UISceneLifecycleMultiplexer _performBlock:withApplicationOfDeactivationReasons:fromReasons:] + 474 19 UIKitCore 0x00007fff23ce6bda -[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:] + 818 20 UIKitCore 0x00007fff23ce646f -[_UISceneLifecycleMultiplexer uiScene:transitionedFromState:withTransitionContext:] + 345 21 UIKitCore 0x00007fff23cee6d8 __186-[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:]_block_invoke + 178 22 UIKitCore 0x00007fff2417c77d +[BSAnimationSettings(UIKit) tryAnimatingWithSettings:actions:completion:] + 871 23 UIKitCore 0x00007fff2428f60e _UISceneSettingsDiffActionPerformChangesWithTransitionContext + 246 24 UIKitCore 0x00007fff23cee3de -[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:] + 361 25 UIKitCore 0x00007fff23b117d5 __64-[UIScene scene:didUpdateWithDiff:transitionContext:completion:]_block_invoke + 797 26 UIKitCore 0x00007fff23b1024e -[UIScene _emitSceneSettingsUpdateResponseForCompletion:afterSceneUpdateWork:] + 253 27 UIKitCore 0x00007fff23b1140e -[UIScene scene:didUpdateWithDiff:transitionContext:completion:] + 208 28 UIKitCore 0x00007fff246c3203 -[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 508 29 UIKitCore 0x00007fff241a4ab4 -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 358 30 FrontBoardServices 0x00007fff25a1b40b -[FBSScene _callOutQueue_agent_didCreateWithTransitionContext:completion:] + 398 31 FrontBoardServices 0x00007fff25a43e55 __94-[FBSWorkspaceScenesClient createWithSceneID:groupID:parameters:transitionContext:completion:]_block_invoke.176 + 102 32 FrontBoardServices 0x00007fff25a28f12 -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] + 209 33 FrontBoardServices 0x00007fff25a43b28 __94-[FBSWorkspaceScenesClient createWithSceneID:groupID:parameters:transitionContext:completion:]_block_invoke + 352 34 libdispatch.dylib 0x0000000103d6274e _dispatch_client_callout + 8 35 libdispatch.dylib 0x0000000103d65656 _dispatch_block_invoke_direct + 295 36 FrontBoardServices 0x00007fff25a695d0 FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK + 30 37 FrontBoardServices 0x00007fff25a692b6 -[FBSSerialQueue _targetQueue_performNextIfPossible] + 433 38 FrontBoardServices 0x00007fff25a6977b -[FBSSerialQueue _performNextFromRunLoopSource] + 22 39 CoreFoundation 0x00007fff20390ede CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 17 40 CoreFoundation 0x00007fff20390dd6 __CFRunLoopDoSource0 + 180 41 CoreFoundation 0x00007fff2039029e __CFRunLoopDoSources0 + 242 42 CoreFoundation 0x00007fff2038a9f7 __CFRunLoopRun + 875 43 CoreFoundation 0x00007fff2038a1a7 CFRunLoopRunSpecific + 567 44 GraphicsServices 0x00007fff2b874d85 GSEventRunModal + 139 45 UIKitCore 0x00007fff246c14df -[UIApplication _run] + 912 46 UIKitCore 0x00007fff246c639c UIApplicationMain + 101 47 Runner 0x00000001000d2eab main + 75 48 libdyld.dylib 0x00007fff2025abbd start + 1 ) libc++abi: terminating with uncaught exception of type NSException *** Terminating app due to uncaught exception ‘NSInternalInconsistencyException’, reason: ‘Sending a message before the FlutterEngine has been run.’ CoreSimulator 757.5 - Device: iPhone 12 Pro Max (8BC45FE7-7ACE-45CE-801C-BC9FC8EA0981) - Runtime: iOS 14.5 (18E182) - DeviceType: iPhone 12 Pro Max terminating with uncaught exception of type NSException (lldb)

How to reproduce the bug

1. Сlone git@github.com:rekab-app/background_locator.git
2. Open folder “example” in android studio
3. Erase All Content and Settings on iOS emulator. Start Location as “City Run”
4. Run main dart in iOS emulator (At first, the app launches fine)
5. Click on the button “start”
6. Click “Allow While Using App”
7. Wait for the display of 30 points
8. Stop application in Android Studio
9. Wait for some time until the “allow example to also use you location even when you are not using the app?” dialog appears. Click “change to always allow”
10. Run “example” from iOS emulator (everything is fine again)
11. Click on the button “start”. the application will display only one point on the screen.
12. Close app “example”
13. After the iOS app crashes on startup

https://user-images.githubusercontent.com/15630163/126048625-d0275c41-46be-4ce5-91a7-368f835ad371.mov

Environment: mac os 11.4 flutter 2.2.3 ios emulator 12 pro max 14.5 xcode 12.5.1 android studio 4.2.2