【Flutter】エラー「Execution failed for task ‘:app:mergeDexDebug’.」の対策

2021.01.16

Flutterでビルドした時のエラーメッセージ「Execution failed for task ‘:app:mergeDexDebug’.の対策方法について紹介します。

【エラー】「Execution failed for task ‘:app:mergeDexDebug’.」

FlutterでAndroidアプリのビルド時に、以下のメッセージが出ることがあります。

注意:/Users/XXXXXX/.pub-cache/hosted/pub.dartlang.org/firebase_core-0.7.0/android/src/main/java/io/flutter/plugins/firebase/core/FlutterFirebaseCorePlugin.javaは非推奨のAPIを使用またはオーバーライドしています。
注意:詳細は、-Xlint:deprecationオプションを指定して再コンパイルしてください。
注意:一部の入力ファイルは非推奨のAPIを使用またはオーバーライドしています。
注意:詳細は、-Xlint:deprecationオプションを指定して再コンパイルしてください。
/Users/XXXXXX/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12+4/android/src/main/java/io/flutter/plugins/sharedpreferences/MethodCallHandlerImpl.java:9: 警告: [deprecation] android.osのAsyncTaskは非推奨になりました
import android.os.AsyncTask;
                 ^
/Users/XXXXXX/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12+4/android/src/main/java/io/flutter/plugins/sharedpreferences/MethodCallHandlerImpl.java:121: 警告: [deprecation] android.osのAsyncTaskは非推奨になりました
    new AsyncTask() {
        ^
/Users/XXXXXX/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12+4/android/src/main/java/io/flutter/plugins/sharedpreferences/MethodCallHandlerImpl.java:121: 警告: [deprecation] AsyncTaskのAsyncTask()は非推奨になりました
    new AsyncTask() {
    ^
/Users/XXXXXX/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12+4/android/src/main/java/io/flutter/plugins/sharedpreferences/MethodCallHandlerImpl.java:123: 警告: [deprecation] AsyncTaskのdoInBackground(Params...)は非推奨になりました
      protected Boolean doInBackground(Void... voids) {
                        ^
  Params,Resultが型変数の場合:
    クラス AsyncTaskで宣言されているParamsはObjectを拡張します
    クラス AsyncTaskで宣言されているResultはObjectを拡張します
/Users/XXXXXX/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12+4/android/src/main/java/io/flutter/plugins/sharedpreferences/MethodCallHandlerImpl.java:121: 警告: [deprecation] AsyncTaskのAsyncTask()は非推奨になりました
    new AsyncTask() {
                                         ^
/Users/XXXXXX/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12+4/android/src/main/java/io/flutter/plugins/sharedpreferences/MethodCallHandlerImpl.java:128: 警告: [deprecation] AsyncTaskのonPostExecute(Result)は非推奨になりました
      protected void onPostExecute(Boolean value) {
                     ^
  Resultが型変数の場合:
    クラス AsyncTaskで宣言されているResultはObjectを拡張します
/Users/XXXXXX/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12+4/android/src/main/java/io/flutter/plugins/sharedpreferences/MethodCallHandlerImpl.java:131: 警告: [deprecation] AsyncTaskのexecute(Params...)は非推奨になりました
    }.execute();
     ^
  Params,Progress,Resultが型変数の場合:
    クラス AsyncTaskで宣言されているParamsはObjectを拡張します
    クラス AsyncTaskで宣言されているProgressはObjectを拡張します
    クラス AsyncTaskで宣言されているResultはObjectを拡張します
警告7個
D8: Cannot fit requested classes in a single dex file (# methods: 80498 > 65536)
com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives:
The number of method references in a .dex file cannot exceed 64K.
Learn how to resolve this issue at https://developer.android.com/tools/building/multidex.html
    at com.android.builder.dexing.D8DexArchiveMerger.getExceptionToRethrow(D8DexArchiveMerger.java:132)
    at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:119)
    at com.android.build.gradle.internal.transforms.DexMergerTransformCallable.call(DexMergerTransformCallable.java:102)
    at com.android.build.gradle.internal.tasks.DexMergingTaskRunnable.run(DexMergingTask.kt:432)
    at com.android.build.gradle.internal.tasks.Workers$ActionFacade.run(Workers.kt:242)
    at org.gradle.workers.internal.AdapterWorkAction.execute(AdapterWorkAction.java:57)
    at org.gradle.workers.internal.DefaultWorkerServer.execute(DefaultWorkerServer.java:63)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1.create(NoIsolationWorkerFactory.java:67)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1.create(NoIsolationWorkerFactory.java:63)
    at org.gradle.internal.classloader.ClassLoaderUtils.executeInClassloader(ClassLoaderUtils.java:97)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1.lambda$execute$0(NoIsolationWorkerFactory.java:63)
    at org.gradle.workers.internal.AbstractWorker$1.call(AbstractWorker.java:44)
    at org.gradle.workers.internal.AbstractWorker$1.call(AbstractWorker.java:41)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:200)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:195)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:75)
    at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:68)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:153)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:68)
    at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:62)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.lambda$call$2(DefaultBuildOperationExecutor.java:76)
    at org.gradle.internal.operations.UnmanagedBuildOperationWrapper.callWithUnmanagedSupport(UnmanagedBuildOperationWrapper.java:54)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:76)
    at org.gradle.workers.internal.AbstractWorker.executeWrappedInBuildOperation(AbstractWorker.java:41)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1.execute(NoIsolationWorkerFactory.java:60)
    at org.gradle.workers.internal.DefaultWorkerExecutor.lambda$submitWork$2(DefaultWorkerExecutor.java:200)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.runExecution(DefaultConditionalExecutionQueue.java:215)
    at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.runBatch(DefaultConditionalExecutionQueue.java:164)
    at org.gradle.internal.work.DefaultConditionalExecutionQueue$ExecutionRunner.run(DefaultConditionalExecutionQueue.java:131)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
    at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
    at java.lang.Thread.run(Thread.java:748)
Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete, position: null
    at Version.fakeStackEntry(Version_2.1.62.java:0)
    at com.android.tools.r8.utils.Y.a(SourceFile:78)
    at com.android.tools.r8.D8.run(D8.java:11)
    at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:117)
    ... 36 more
Caused by: com.android.tools.r8.utils.b: Cannot fit requested classes in a single dex file (# methods: 80498 > 65536)
    at com.android.tools.r8.utils.T0.error(SourceFile:1)
    at com.android.tools.r8.utils.T0.a(SourceFile:2)
    at com.android.tools.r8.dex.P.a(SourceFile:740)
    at com.android.tools.r8.dex.P$h.a(SourceFile:7)
    at com.android.tools.r8.dex.b.a(SourceFile:14)
    at com.android.tools.r8.dex.b.b(SourceFile:25)
    at com.android.tools.r8.D8.d(D8.java:133)
    at com.android.tools.r8.D8.b(D8.java:1)
    at com.android.tools.r8.utils.Y.a(SourceFile:36)
    ... 38 more


FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:mergeDexDebug'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
   > com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives:
     The number of method references in a .dex file cannot exceed 64K.
     Learn how to resolve this issue at https://developer.android.com/tools/building/multidex.html

* 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 3m 0s
[!] The shrinker may have failed to optimize the Java bytecode.
    To disable the shrinker, pass the `--no-shrink` flag to this command.
    To learn more, see: https://developer.android.com/studio/build/shrink-code
Exception: Gradle task assembleDebug failed with exit code 1

● 「app/build.gradle」に下記の1行を追加することで解決しました。

android {
   defaultConfig {
       // ...
       multiDexEnabled true // 追加
   }
}
【Flutter入門】iOS、Android、Windowsアプリ開発
FlutterによるiOS、Android、Windowsアプリ開発について入門者向けに紹介します。
flutter.joho.info
2019.11.17

コメント