[BUG] iOS build fails with "non-modular header" in firebase_messaging on Flutter Beta & Xcode 26.0

[jigoo1028]

Is there an existing issue for this?

• I have searched the existing issues.

Which plugins are affected?

Messaging

Which platforms are affected?

iOS

Description

Describe the issue

When building a Flutter project for iOS using a combination of the latest Flutter Beta SDK, the latest FlutterFire plugins, and the new Xcode 26.0, the build consistently fails. The error is a Lexical or Preprocessor Issue: Include of non-modular header inside framework module, specifically pointing to firebase_messaging.FLTFirebaseMessagingPlugin.

This issue persists even after performing a complete and thorough reset of the development environment, including creating a new macOS user account, reinstalling all tools (Xcode, Flutter, CocoaPods, Homebrew), and regenerating the native project folders.

Expected behavior

The application should build and launch successfully on an iOS simulator or a physical device.

Actual behavior

The Xcode build fails with the following error:
Failed to build iOS app
Could not build the precompiled application for the device.
Lexical or Preprocessor Issue (Xcode): Include of non-modular header inside framework module 'firebase_messaging.FLTFirebaseMessagingPlugin': '/Users/jigoo/Developer/diastory/ios/Pods/Headers/Public/Firebase/Firebase.h'
/Users/jigoo/.pub-cache/hosted/pub.dev/firebase_messaging-15.1.0/ios/Classes/FLTFirebaseMessagingPlugin.h:11:8

Additional context

This does not appear to be a standard configuration issue. We have exhaustively tried every known solution, including but not limited to:

• Creating a brand new macOS user account.
• Reinstalling all development tools from scratch.
• Regenerating the native ios and android folders with flutter create ..
• Trying all variations of use_modular_headers! in the Podfile.
• Manually forcing modular headers on each individual Firebase pod.
• Cleaning every possible cache (flutter clean, pod cache clean, deleting DerivedData, etc.).
• Switching between Flutter's stable and beta channels.

The issue seems to be a fundamental incompatibility between the toolchain versions.

Reproducing the issue

Steps to reproduce

1. Set up a clean macOS environment with Xcode 26.0 and the latest Flutter Beta channel SDK.
2. Create a new Flutter project (flutter create my_app).
3. Add the latest versions of FlutterFire plugins to pubspec.yaml (including firebase_core, firebase_auth, and firebase_messaging).
4. Run flutter pub get.
5. Configure the ios/Podfile to use platform :ios, '15.0'.
6. Run pod install in the ios directory (this completes successfully).
7. Attempt to build the app for an iOS target (flutter run). The build will fail during the Xcode build phase.

Firebase Core version

3.1.1

Flutter Version

3.37.0

Relevant Log Output

Flutter dependencies

environment:
sdk: ">=3.9.0 <4.0.0"

dependencies:
flutter:
sdk: flutter
cloud_functions: ^5.0.1
provider: ^6.1.2
cached_network_image: ^3.3.1
permission_handler: ^11.3.1
cupertino_icons: ^1.0.8
google_mobile_ads: ^5.1.0
firebase_remote_config: ^5.0.1
url_launcher: ^6.3.0
shared_preferences: ^2.2.3
geolocator: ^12.0.0
geocoding: ^3.0.0
json_annotation: ^4.9.0
path_provider: ^2.1.3
image_picker: ^1.1.2
path: ^1.9.0
fl_chart: ^0.68.0
uuid: ^4.4.0
flutter_local_notifications: ^17.1.2
timezone: ^0.9.4
firebase_core:
firebase_messaging: 15.0.0
cloud_firestore: ^5.0.1
firebase_auth: ^5.1.1
firebase_storage: ^12.0.1
google_sign_in: ^6.2.1
sign_in_with_apple: ^6.1.1
font_awesome_flutter: ^10.7.0
share_plus: ^9.0.0
lottie: ^3.1.2
flutter_localizations:
sdk: flutter
intl: any

dev_dependencies:
flutter_test:
sdk: flutter
flutter_lints: ^3.0.0
flutter_launcher_icons: ^0.13.1
build_runner: ^2.4.6
json_serializable: ^6.7.1

flutter_icons:
android: true
ios: true
image_path: "assets/icon/app_icon.png"
remove_alpha_ios: true

flutter:
generate: true
uses-material-design: true

assets:
- assets/

Additional context and comments

No response

[MichaelVerdon]

Hi there can you please refresh your pods by doing the following:

cd ios/
pod cache clean --all
pod deintegrate
pod install

Then after include:

use_frameworks!

In your podfile. Then open your XCode and search for Allow Non-modular Includes in Framework Modules then set this to yes. Afterwards try clean your project and build again. The steps should help ensure it is all handled properly

[google-oss-bot]

Hey @jigoo1028. We need more information to resolve this issue but there hasn't been an update in 7 weekdays. I'm marking the issue as stale and if there are no new updates in the next 7 days I will close it automatically.

If you have more information that will help us get to the bottom of this, just add a comment!