[Bug]: symbol: class NonNull

[Aqitaniya]

Required Reading

• Confirmed

Plugin Version

1.3.7

Flutter Doctor

/flutter/bin/flutter doctor --verbose
[!] Flutter (Channel stable, 3.27.4, on macOS 15.1.1 24B91 darwin-arm64, locale en-GB)
    • Flutter version 3.27.4 on channel stable at /flutter
    ! Warning: `dart` on your path resolves to /usr/local/Cellar/dart/3.5.4/libexec/bin/dart, which is not inside your current Flutter SDK checkout at /flutter. Consider adding /flutter/bin to the front of your path.
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision d8a9f9a52e (7 days ago), 2025-01-31 16:07:18 -0500
    • Engine revision 82bd5b7209
    • Dart version 3.6.2
    • DevTools version 2.40.3
    • 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 (Android SDK version 34.0.0)
    • Android SDK at /Library/Android/sdk
    • Platform android-35, build-tools 34.0.0
    • ANDROID_HOME = /Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b829.9-10027231)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 16B40
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2022.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b829.9-10027231)

[✓] Connected device (5 available)
    • Redmi 6A (mobile)               • 0867a84f7d2b              • android-arm    • Android 8.1.0 (API 27)
    • Aquitania (mobile)              • 00008110-000115011E78801E • ios            • iOS 18.3 22D63
    • macOS (desktop)                 • macos                     • darwin-arm64   • macOS 15.1.1 24B91 darwin-arm64
    • Mac Designed for iPad (desktop) • mac-designed-for-ipad     • darwin         • macOS 15.1.1 24B91 darwin-arm64
    • Chrome (web)                    • chrome                    • web-javascript • Google Chrome 132.0.6834.160
    ! Error: Browsing on the local area network for iPhone Alex. Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac.
      The device must be opted into Developer Mode to connect wirelessly. (code -27)
    ! Error: Browsing on the local area network for Apple Watch — Oleksandr. Ensure the device is unlocked and discoverable via Bluetooth. (code -27)
    ! Error: Browsing on the local area network for iPhone (Вадим). Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac.
      The device must be opted into Developer Mode to connect wirelessly. (code -27)

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

! Doctor found issues in 1 category.

Mobile operating-system(s)

• iOS
• Android

Device Manufacturer(s) and Model(s)

no

Device operating-systems(s)

no

What happened?

After update to Kotlin 2.1.10 I have get such errors when try create build for Android:

/.pub-cache/hosted/pub.dev/background_fetch-1.3.7/android/src/main/java/com/transistorsoft/flutter/backgroundfetch/HeadlessTask.java:8: error: cannot find symbol
import androidx.annotation.Keep;
^
symbol: class Keep
location: package androidx.annotation
/.pub-cache/hosted/pub.dev/background_fetch-1.3.7/android/src/main/java/com/transistorsoft/flutter/backgroundfetch/HeadlessTask.java:9: error: cannot find symbol
import androidx.annotation.NonNull;
^
symbol: class NonNull
location: package androidx.annotation
/.pub-cache/hosted/pub.dev/background_fetch-1.3.7/android/src/main/java/com/transistorsoft/flutter/backgroundfetch/HeadlessTask.java:11: error: package com.transistorsoft.tsbackgroundfetch does not exist
import com.transistorsoft.tsbackgroundfetch.BGTask;
^
/.pub-cache/hosted/pub.dev/background_fetch-1.3.7/android/src/main/java/com/transistorsoft/flutter/backgroundfetch/HeadlessTask.java:12: error: package com.transistorsoft.tsbackgroundfetch does not exist
import com.transistorsoft.tsbackgroundfetch.BackgroundFetch;
^
/.pub-cache/hosted/pub.dev/background_fetch-1.3.7/android/src/main/java/com/transistorsoft/flutter/backgroundfetch/HeadlessTask.java:21: error: package io.flutter.embedding.engine does not exist
import io.flutter.embedding.engine.FlutterEngine;

Plugin Code and/or Config

Future<void> configureScheduleTask() async {
    final int status = await BackgroundFetch.configure(BackgroundFetchConfig(
        minimumFetchInterval: 15,
        forceAlarmManager: true,
        stopOnTerminate: false,
        startOnBoot: true,
        enableHeadless: true,
        requiresBatteryNotLow: false,
        requiresCharging: false,
        requiresStorageNotLow: false,
        requiresDeviceIdle: false,
        requiredNetworkType: NetworkType.NONE
    ), _onBackgroundFetch, _onBackgroundFetchTimeout);
    print('[BackgroundFetch] configure success: $status');
  }

@pragma('vm:entry-point')
void backgroundFetchHeadlessTask(HeadlessTask task) async {
      var taskId = task.taskId;
      var timeout = task.timeout;
      if (timeout) {
            print("[BackgroundFetch] Headless task timed-out: $taskId");
            BackgroundFetch.finish(taskId);
            return;
      }
      print("[BackgroundFetch] Headless event received: $taskId");
      final job = HelperJobs();
      if (taskId == 'flutter_background_fetch') {
            job.initJob();
      }
      BackgroundFetch.finish(taskId);
}

Relevant log output

[christocracy]

This is most likely an issue with your own app's gradle config.

My plugin does not use Kotlin at all.

Googling, I found this: https://stackoverflow.com/questions/76374809/android-studio-cannot-resolve-symbol-nonnull-import-androidx-annotation-nonn