app:mergeProjectDexDebugのエラーが出てしまう

Question

動画を参考にrealmの使い方を勉強していたのですが、エラーが出てしまい他サイトを参考にしても直りません。助けてくださる方いらっしゃいましたらよろしくお願いいたします。

AGPBI: {"kind":"error","text":"Type androidx.activity.R$layout is defined multiple times: C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\androidx\activity\R$layout.dex, C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\c71e33c820d6c2e1e90ca4403d011c9c6ec504582e69b54d7412a5d84dc8430a_0.jar:classes.dex","sources":[{"file":"C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\androidx\activity\R$layout.dex"}],"tool":"D8"}
com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: 
Type androidx.activity.R$layout is defined multiple times: C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\androidx\activity\R$layout.dex, C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\c71e33c820d6c2e1e90ca4403d011c9c6ec504582e69b54d7412a5d84dc8430a_0.jar:classes.dex
Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.
	at com.android.builder.dexing.D8DexArchiveMerger.getExceptionToRethrow(D8DexArchiveMerger.java:132)
	at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:119)
	at com.android.build.gradle.internal.transforms.DexMergerTransformCallable.call(DexMergerTransformCallable.java:102)
	at com.android.build.gradle.internal.tasks.DexMergingTaskRunnable.run(DexMergingTask.kt:432)
	at com.android.build.gradle.internal.tasks.Workers$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$1.call(AbstractWorker.java:41)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:409)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:399)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:157)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:242)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:150)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:94)
	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
	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$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
	at java.lang.Thread.run(Thread.java:748)
Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete, origin: C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\androidx\activity\R$layout.dex
	at Version.fakeStackEntry(Version_2.1.75.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)
	... 33 more
Caused by: com.android.tools.r8.utils.b: Type androidx.activity.R$layout is defined multiple times: C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\androidx\activity\R$layout.dex, C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\c71e33c820d6c2e1e90ca4403d011c9c6ec504582e69b54d7412a5d84dc8430a_0.jar:classes.dex
	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.utils.R0.b(SourceFile:6)
	at com.android.tools.r8.utils.R0.a(SourceFile:24)
	at com.android.tools.r8.utils.R0.a(SourceFile:10)
	at java.util.concurrent.ConcurrentHashMap.merge(ConcurrentHashMap.java:1990)
	at com.android.tools.r8.utils.R0.a(SourceFile:6)
	at com.android.tools.r8.graph.Q0$c.f(SourceFile:3)
	at com.android.tools.r8.dex.a.a(SourceFile:298)
	at com.android.tools.r8.dex.a.a(SourceFile:226)
	at com.android.tools.r8.D8.d(D8.java:6)
	at com.android.tools.r8.D8.b(D8.java:1)
	at com.android.tools.r8.utils.Y.a(SourceFile:36)
	... 35 more


Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete, origin: C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\androidx\activity\R$layout.dex

Caused by: com.android.tools.r8.utils.b: Type androidx.activity.R$layout is defined multiple times: C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\androidx\activity\R$layout.dex, C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\c71e33c820d6c2e1e90ca4403d011c9c6ec504582e69b54d7412a5d84dc8430a_0.jar:classes.dex

Execution failed for task ':app:mergeProjectDexDebug'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
   > com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: 
     Type androidx.activity.R$layout is defined multiple times: C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\androidx\activity\R$layout.dex, C:\Users\user\AndroidStudioProjects\TodoList\app\build\intermediates\project_dex_archive\debug\out\c71e33c820d6c2e1e90ca4403d011c9c6ec504582e69b54d7412a5d84dc8430a_0.jar:classes.dex
     Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.

plugins {
    id 'com.android.application'
    id 'realm-android'
}


android {
    compileSdkVersion 30
    buildToolsVersion "30.0.2"

    defaultConfig {
        applicationId "com.example.todolist"
        minSdkVersion 16
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        multiDexEnabled true
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

dependencies {

    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'com.google.android.material:material:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
    implementation 'androidx.navigation:navigation-fragment:2.2.2'
    implementation 'androidx.navigation:navigation-ui:2.2.2'
    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
    implementation 'io.realm:android-adapters:1.0.1'
}

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath "com.android.tools.build:gradle:4.1.1"
        classpath "io.realm:realm-gradle-plugin:10.0.1"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

Answer 1

realmは使ったことありませんが、
エラーログの4行目に表示されている通り、
Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.

app:mergeProjectDexDebugの原因としては以下の状況が考えられます。

• 使用している複数のライブラリ内で同じクラスを参照している。
• それらが同じクラスであるにもかかわらずバージョンに食い違いがあり、別々に読み込まれている。

結果的にモジュール内に同名、別バージョンのクラスが存在し、競合する。

最新のライブラリと旧式のライブラリを混同して用いたりすると起きやすいです。
すべてバージョンとしては最新を使っていても、メンテナンスが止まっている、または遅れていると旧バージョンの依存関係が含まれることがあります。

対処方法としては：

• すべてのライブラリが最新であることを確認する。
• （すべて最新であれば）ライブラリを一つずつ外して（一つ戻して）コンパイルを走らせる。
• どの時点でエラーが出なくなるかを検証。
• 外せるライブラリであれば除外を検討する。
• 1つだけ最新が混じっていて他と競合していることもあるので、敢えてバージョンを落とすなどの対処方法があります。