Finished with error: Gradle task assembleDebug failed with exit code 1

Question

Launching lib\main.dart on HTC One M9PLUS in debug mode... Initializing gradle... Resolving dependencies... Gradle task 'assembleDebug'... registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection) registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection) registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection) registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection) registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection) C:\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.9.0\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java:9: error: cannot find symbol import androidx.annotation.NonNull;
                          ^   symbol:   class NonNull   location: package androidx.annotation C:\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.9.0\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java:10: error: cannot find symbol import androidx.annotation.Nullable;
                          ^   symbol:   class Nullable   location: package androidx.annotation C:\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.9.0\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java:253: error: cannot find symbol
          public void onFailure(@NonNull Exception e) {
                                 ^   symbol: class NonNull C:\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.9.0\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java:274: error: cannot find symbol
                    public Void apply(@NonNull Transaction transaction)
                                       ^   symbol: class NonNull C:\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.9.0\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java:272: error: cannot find symbol
                    @Nullable
                     ^   symbol: class Nullable C:\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.9.0\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java:503: error: cannot find symbol
                    public void onFailure(@NonNull Exception e) {
                                           ^   symbol: class NonNull C:\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.9.0\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java:558: error: cannot find symbol
                    public void onFailure(@NonNull Exception e) {
                                           ^   symbol: class NonNull 7 errors

FAILURE: Build failed with an exception.

* What went wrong: Execution failed for task ':cloud_firestore:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

* Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 26s Finished with error: Gradle task assembleDebug failed with exit code 1

I just tried to add the firebase to the project

Answer 1

The primary problem looks to be that you are using version 0.9.0 of the cloud_firestore plugin which has been migrated to AndroidX, but your project has not been migrated. So, it would appear the two options are to either use the previous version of the cloud_firestore plugin or migrate your project to AndroidX.

To migrate your project to AndroidX, follow the link I mention in my comment above (Firebase auth plugin crash IOS and android #27422) and under the Android section of my initial response (posted under username app-o-matix), follow Steps 1-3. The remaining steps and follow up post may be of help in avoiding additional problems.

Here are Steps 1-3 from the linked page (I use IntelliJ Idea CE and select Swift and Kotlin in creating my Flutter projects):

1) Open the Android portion of your Flutter project in Android Studio. Make sure you are using Android Studio 3.3. (I closed IntelliJ Idea altogether, opened Android Studio, clicked on File > Open, and navigated to the ~/IdeaProjects/[my_project]/android folder in my Flutter project. Upon opening the Android project followed by Android Studio starting to sync it, a message/pop-up appeared asking if it could update the Gradle plugin, so I let it. It was upgraded to version 3.3.0.)

2) Add the following 2 lines to the bottom of the [my_project]/android/gradle.properties file:

android.useAndroidX=true
android.enableJetifier=true

Note: I'm not sure if android.enableJetifier=true could have been, or should have been, set to false. Perhaps someone else can clarify under which conditions it should be true vs false. I believe it has something to do with whether or not the project has additional libraries that haven't yet been migrated to AndroidX, but, if my belief is correct, I don't know if when this setting is set to true it means Android Studio will migrate these libraries to AndroidX or that it will make code adjustments to account for the fact that the libraries aren't yet AndroidX compatible. Or maybe I'm totally wrong and it is something else altogether.

3) In the Android Studio main menus, select Refactor > Migrate to Androidx..., saving a backup of your project to a .zip file. Follow this with File > Save All and then quit Android Studio.

As an extra measure after the migration, in IntelliJ Idea I run Tools > Flutter > Flutter Clean, File > Save All, File > Invalidate Caches and Restart where I choose to both invalidate caches and restart, then after the restart Tools > Flutter > Flutter Packages Get.