Newly created Flutter app crashes on Xcode 26 & macOS 26 betas

### Steps to reproduce

1. Make sure your macOS, iOS, and Xcode version match that in `flutter doctor` below
2. `flutter create my_app`
3. `flutter run` on a physical iOS 26 devices

App crashes

### Expected results

App should not crash

### Actual results

The Flutter CLI crashes with 
```
[   +8 ms] Fail to connect to service protocol: http://127.0.0.1:49635/yMfltgm0OTw=/: HttpException: Connection closed before full header was received, uri = http://127.0.0.1:49635/yMfltgm0OTw=/ws
[        ] Error connecting to the service protocol: failed to connect to http://127.0.0.1:49635/yMfltgm0OTw=/ HttpException: Connection closed before full header was received, uri = http://127.0.0.1:49635/yMfltgm0OTw=/ws
[        ] "flutter run" took 16,131ms.
[   +3 ms] 
           #0      throwToolExit (package:flutter_tools/src/base/common.dart:34:3)
           #1      RunCommand.runCommand (package:flutter_tools/src/commands/run.dart:897:9)
           <asynchronous suspension>
           #2      FlutterCommand.run.<anonymous closure> (package:flutter_tools/src/runner/flutter_command.dart:1559:27)
           <asynchronous suspension>
           #3      AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:154:19)
           <asynchronous suspension>
           #4      CommandRunner.runCommand (package:args/command_runner.dart:212:13)
           <asynchronous suspension>
           #5      FlutterCommandRunner.runCommand.<anonymous closure> (package:flutter_tools/src/runner/flutter_command_runner.dart:487:9)
           <asynchronous suspension>
           #6      AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:154:19)
           <asynchronous suspension>
           #7      FlutterCommandRunner.runCommand (package:flutter_tools/src/runner/flutter_command_runner.dart:422:5)
           <asynchronous suspension>
           #8      run.<anonymous closure>.<anonymous closure> (package:flutter_tools/runner.dart:104:11)
           <asynchronous suspension>
           #9      AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:154:19)
           <asynchronous suspension>
           #10     main (package:flutter_tools/executable.dart:103:3)
           <asynchronous suspension>


[        ] Running 3 shutdown hooks
[        ] Shutdown hooks complete
[        ] exiting with code 2

```

But the real issue is that the app is crashing on launch, so Flutter is failing to connect.

### Code sample

Use create template

### Screenshots or Video

<details open>
<summary>Screenshots / Video demonstration</summary>

[Upload media here]

</details>


### Logs

<details open><summary>Logs</summary>

```console
Incident Identifier: 8665268E-6E95-4732-AB22-0237466E7889
CrashReporter Key:   3ea869c1f7a8514ab79b7d352d0f6ee2539c4a57
Hardware Model:      iPad14,3
Process:             Runner [745]
Path:                /private/var/containers/Bundle/Application/7DD0C2B9-BBB1-40D1-9D28-885B248C4DE5/Runner.app/Runner
Identifier:          com.example.ideTesting
Version:             1.0.0 (1)
Code Type:           ARM-64 (Native)
Role:                Foreground
Parent Process:      launchd [1]
Coalition:           com.example.ideTesting [948]

Date/Time:           2025-12-03 13:27:32.3819 -0600
Launch Time:         2025-12-03 13:27:32.2615 -0600
OS Version:          iPhone OS 26.2 (23C5027f)
Release Type:        Beta
Report Version:      104

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Subtype: KERN_INVALID_ADDRESS at 0x0000000000000000
Exception Codes: 0x0000000000000001, 0x0000000000000000
VM Region Info: 0 is not in any region.  Bytes before following region: 4332027904
      REGION TYPE                 START - END      [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      UNUSED SPACE AT START
--->  
      __TEXT                   102358000-102364000 [   48K] r-x/r-x SM=COW  /var/containers/Bundle/Application/7DD0C2B9-BBB1-40D1-9D28-885B248C4DE5/Runner.app/Runner
Termination Reason: SIGNAL 11 Segmentation fault: 11
Terminating Process: exc handler [745]

Triggered by Thread:  0

Thread 0 name:   Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0   Flutter                       	       0x104dcd030 -[VSyncClient initWithTaskRunner:callback:] + 300
1   Flutter                       	       0x104db7dd4 -[FlutterViewController createTouchRateCorrectionVSyncClientIfNeeded] + 216
2   Flutter                       	       0x104db5940 -[FlutterViewController viewDidLoad] + 396
3   UIKitCore                     	       0x19ff27efc -[UIViewController _sendViewDidLoadWithAppearanceProxyObjectTaggingEnabled] + 83
4   UIKitCore                     	       0x19ff1911c -[UIViewController loadViewIfRequired] + 943
5   UIKitCore                     	       0x19ff18d4c -[UIViewController view] + 23
6   UIKitCore                     	       0x19ff5e714 -[UIWindow addRootViewControllerViewIfPossible] + 135
7   UIKitCore                     	       0x1a1360234 -[UIWindow _updateLayerOrderingAndSetLayerHidden:actionBlock:] + 171
8   UIKitCore                     	       0x1a13605d8 -[UIWindow _setHidden:forced:] + 259
9   UIKitCore                     	       0x19ff717c4 -[UIWindow _mainQueue_makeKeyAndVisible] + 39
10  UIKitCore                     	       0x1a132cd48 -[UIApplication _callInitializationDelegatesWithActions:forScene:payload:fromOriginatingProcess:] + 3239
11  UIKitCore                     	       0x1a1330ce8 -[UIApplication _runWithMainScene:transitionContext:completion:] + 787
12  UIKitCore                     	       0x1a093bcbc -[_UISceneLifecycleMultiplexer completeApplicationLaunchWithFBSScene:transitionContext:] + 115
13  UIKitCore                     	       0x19ffec60c _UIScenePerformActionsWithLifecycleActionMask + 111
14  UIKitCore                     	       0x1a093c538 __101-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]_block_invoke + 251
15  UIKitCore                     	       0x1a093c044 -[_UISceneLifecycleMultiplexer _performBlock:withApplicationOfDeactivationReasons:fromReasons:] + 211
16  UIKitCore                     	       0x1a093c350 -[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:] + 607
17  UIKitCore                     	       0x1a093bddc -[_UISceneLifecycleMultiplexer uiScene:transitionedFromState:withTransitionContext:] + 243
18  UIKitCore                     	       0x1a094725c __186-[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:]_block_invoke + 147
19  UIKitCore                     	       0x1a0db9928 +[BSAnimationSettings(UIKit) tryAnimatingWithSettings:fromCurrentState:actions:completion:] + 735
20  UIKitCore                     	       0x19ffed424 _UISceneSettingsDiffActionPerformChangesWithTransitionContextAndCompletion + 223
21  UIKitCore                     	       0x1a0946f58 -[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:] + 315
22  UIKitCore                     	       0x1a0786174 __64-[UIScene scene:didUpdateWithDiff:transitionContext:completion:]_block_invoke.218 + 615
23  UIKitCore                     	       0x1a0785208 -[UIScene _emitSceneSettingsUpdateResponseForCompletion:afterSceneUpdateWork:] + 207
24  UIKitCore                     	       0x1a0785de0 -[UIScene scene:didUpdateWithDiff:transitionContext:completion:] + 243
25  UIKitCore                     	       0x1a132fcb4 -[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 475
26  UIKitCore                     	       0x1a0de2718 -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 287
27  FrontBoardServices            	       0x1ba5bed28 __95-[FBSScene _callOutQueue_didCreateWithTransitionContext:alternativeCreationCallout:completion:]_block_invoke + 363
28  FrontBoardServices            	       0x1ba5bf1e0 -[FBSScene _callOutQueue_maybeCoalesceClientSettingsUpdates:] + 127
29  FrontBoardServices            	       0x1ba5beb40 -[FBSScene _callOutQueue_didCreateWithTransitionContext:alternativeCreationCallout:completion:] + 435
30  FrontBoardServices            	       0x1ba62ceac __93-[FBSWorkspaceScenesClient _callOutQueue_sendDidCreateForScene:transitionContext:completion:]_block_invoke.341 + 287
31  FrontBoardServices            	       0x1ba5cc8a0 -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] + 167
32  FrontBoardServices            	       0x1ba5e9738 -[FBSWorkspaceScenesClient _callOutQueue_sendDidCreateForScene:transitionContext:completion:] + 479
33  FrontBoardServices            	       0x1ba5eb09c __92-[FBSWorkspaceScenesClient createSceneWithIdentity:parameters:transitionContext:completion:]_block_invoke_2 + 267
34  FrontBoardServices            	       0x1ba5cc8a0 -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] + 167
35  libdispatch.dylib             	       0x1d33e27ec _dispatch_client_callout + 15
36  libdispatch.dylib             	       0x1d33cdbb4 _dispatch_block_invoke_direct + 283
37  BoardServices                 	       0x1b1d0c1d4 __BSSERVICEMAINRUNLOOPQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 51
38  BoardServices                 	       0x1b1d0c054 BSServiceMainRunLoopSourceHandler + 223
39  CoreFoundation                	       0x19a625f24 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 27
40  CoreFoundation                	       0x19a625e98 __CFRunLoopDoSource0 + 171
41  CoreFoundation                	       0x19a603b30 __CFRunLoopDoSources0 + 331
42  CoreFoundation                	       0x19a5da6d8 __CFRunLoopRun + 819
43  CoreFoundation                	       0x19a5d9a6c _CFRunLoopRunSpecificWithOptions + 531
44  GraphicsServices              	       0x23bace498 GSEventRunModal + 119
45  UIKitCore                     	       0x19ffb17cc -[UIApplication _run] + 791
46  UIKitCore                     	       0x19ff59f40 UIApplicationMain + 335
47  UIKitCore                     	       0x1a008608c 0x1a0086025 + 103
48  Runner.debug.dylib            	       0x1023a05d0 static UIApplicationDelegate.main() + 128
49  Runner.debug.dylib            	       0x1023a0540 static AppDelegate.$main() + 44
50  Runner.debug.dylib            	       0x1023a064c __debug_main_executable_dylib_entry_point + 28
51  dyld                          	       0x1975b6e28 start + 7115
```

</details>


### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[!] Flutter (Channel [user-branch], 3.38.3, on macOS 26.2 25C56 darwin-arm64, locale en-US) [105ms]
    • Framework revision 19074d12f7 (13 days ago), 2025-11-20 17:53:13 -0500
    • Engine revision 13e658725d
    • Dart version 3.10.1
    • DevTools version 2.51.1
    • Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop, enable-android,
      enable-ios, cli-animations, enable-native-assets, omit-legacy-version-file, enable-lldb-debugging
    • If those were intentional, you can disregard the above warnings; however it is recommended to use "git" directly
      to perform update checks and upgrades.

[✗] Android toolchain - develop for Android devices [57ms]
    ✗ Unable to locate Android SDK.
      Install Android Studio from: https://developer.android.com/studio/index.html
      On first launch it will assist you in installing the Android SDK components.
      (or visit https://flutter.dev/to/macos-android-setup for detailed instructions).
      If the Android SDK has been installed to a custom location, please use
      `flutter config --android-sdk` to update to that location.


[!] Xcode - develop for iOS and macOS (Xcode 26.2) [146ms]
    • Xcode at /Applications/Xcode-beta.app/Contents/Developer
    • Build 17C5038g
    ✗ CocoaPods not installed.
        CocoaPods is a package manager for iOS or macOS platform code.
        Without CocoaPods, plugins will not work on iOS or macOS.
        For more info, see https://flutter.dev/to/platform-plugins
      For installation instructions, see https://guides.cocoapods.org/using/getting-started.html#installation

[✗] Chrome - develop for the web (Cannot find Chrome executable at /Applications/Google Chrome.app/Contents/MacOS/Google
    Chrome) [4ms]
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.

[✓] Connected device (2 available) [5.5s]
    • Victoria’s iPad (mobile) • 00008112-0006112A3C03401E • ios          • iOS 26.2 23C5027f
    • macOS (desktop)          • macos                     • darwin-arm64 • macOS 26.2 25C56 darwin-arm64

[✓] Network resources [165ms]
    • All expected network resources are available.

! Doctor found issues in 4 categories.
```

</details>


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Uh oh!

Newly created Flutter app crashes on Xcode 26 & macOS 26 betas #179422

Steps to reproduce

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Uh oh!

Newly created Flutter app crashes on Xcode 26 & macOS 26 betas #179422

Description

Steps to reproduce

Expected results

Actual results

Code sample

Screenshots or Video

Logs

Flutter Doctor output

Metadata

Metadata

Assignees

Labels

Type

Fields

Projects

Milestone

Relationships

Development

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