Execution failed for task ‘:app:checkDebugAarMetadata’.エラーでビルドできない

数ヶ月ぶりにAndroid Studioでアプリのビルドを走らせたら大量にエラーが出て動かなかったので解決方法をメモ

エラーメッセージ詳細

実際のエラーメッセージは以下のような感じ。

Execution failed for task ':app:checkDebugAarMetadata'.
> Multiple task action failures occurred:
   > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
      > The minCompileSdk (31) specified in a
        dependency's AAR metadata (META-INF/com/android/build/gradle/aar-metadata.properties)
        is greater than this module's compileSdkVersion (android-30).
        Dependency: androidx.appcompat:appcompat:1.4.1.
        AAR metadata file: C:\Users\■■■■\.gradle\caches\transforms-2\files-2.1\21c3ecf98e280316449ae27cb17f9a1a\appcompat-1.4.1\META-INF\com\android\build\gradle\aar-metadata.properties.
   > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
      > The minCompileSdk (31) specified in a
        dependency's AAR metadata (META-INF/com/android/build/gradle/aar-metadata.properties)
        is greater than this module's compileSdkVersion (android-30).
        Dependency: androidx.appcompat:appcompat-resources:1.4.1.
        AAR metadata file: C:\Users\■■■■\.gradle\caches\transforms-2\files-2.1\29eb1277873f8d6c55982bb6830f296b\jetified-appcompat-resources-1.4.1\META-INF\com\android\build\gradle\aar-metadata.properties.
   > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
      > The minCompileSdk (31) specified in a
        dependency's AAR metadata (META-INF/com/android/build/gradle/aar-metadata.properties)
        is greater than this module's compileSdkVersion (android-30).
        Dependency: androidx.emoji2:emoji2-views-helper:1.0.0.
        AAR metadata file: C:\Users\■■■■\.gradle\caches\transforms-2\files-2.1\3450f576bbbb5c124422a09a8929654b\jetified-emoji2-views-helper-1.0.0\META-INF\com\android\build\gradle\aar-metadata.properties.
   > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
      > The minCompileSdk (31) specified in a
        dependency's AAR metadata (META-INF/com/android/build/gradle/aar-metadata.properties)
        is greater than this module's compileSdkVersion (android-30).
        Dependency: androidx.emoji2:emoji2:1.0.0.
        AAR metadata file: C:\Users\■■■■\.gradle\caches\transforms-2\files-2.1\51c794e8d58f2add1b6e1035ee7c058d\jetified-emoji2-1.0.0\META-INF\com\android\build\gradle\aar-metadata.properties.
   > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
      > The minCompileSdk (31) specified in a
        dependency's AAR metadata (META-INF/com/android/build/gradle/aar-metadata.properties)
        is greater than this module's compileSdkVersion (android-30).
        Dependency: androidx.core:core:1.7.0.
        AAR metadata file: C:\Users\■■■■\.gradle\caches\transforms-2\files-2.1\9b4bbe17406ebdd5cecd894aeda4ed80\core-1.7.0\META-INF\com\android\build\gradle\aar-metadata.properties.
   > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
      > The minCompileSdk (31) specified in a
        dependency's AAR metadata (META-INF/com/android/build/gradle/aar-metadata.properties)
        is greater than this module's compileSdkVersion (android-30).
        Dependency: androidx.lifecycle:lifecycle-process:2.4.0.
        AAR metadata file: C:\Users\■■■■\.gradle\caches\transforms-2\files-2.1\e539e26c730ec8f29e3c4a27f918073b\jetified-lifecycle-process-2.4.0\META-INF\com\android\build\gradle\aar-metadata.properties.
   > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckAarMetadataWorkAction
      > The minCompileSdk (31) specified in a
        dependency's AAR metadata (META-INF/com/android/build/gradle/aar-metadata.properties)
        is greater than this module's compileSdkVersion (android-30).
        Dependency: androidx.lifecycle:lifecycle-runtime:2.4.0.
        AAR metadata file: C:\Users\■■■■\.gradle\caches\transforms-2\files-2.1\ff81fc826eef84982d02d149abc4bcd7\lifecycle-runtime-2.4.0\META-INF\com\android\build\gradle\aar-metadata.properties.

大量に出ているけど、基本的には同じ現象が複数の依存関係にあるAARに発生している模様。
抜き出して一個だけ確認してみる。

The minCompileSdk (31) specified in a
dependency's AAR metadata is greater than this module's compileSdkVersion (android-30).

雑に翻訳すると”依存関係の AAR メタデータで指定された minCompileSdk (31) が、このモジュールの compileSdkVersion (android-30) より大きい”との事なので、手っ取り早くこのモジュールのcompileSdkVersionを31にしてあげることにする。

build.gradlのcompileSdkVersionを31にする

　build.gradl(:app)のcompileSdkVersionを31にする。

android {
    compileSdkVersion 30 // これを31にする
    buildToolsVersion "30.0.1"

    defaultConfig {
        applicationId "com.◆◆◆◆◆◆.test"
        minSdkVersion 29
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

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

ここをこう。

compileSdkVersion 30→compileSdkVersion 31

これで保存してもう一度ビルドしたら。”BUILD SUCCESSFUL in 2s”でビルドが通って動いた。

自分のアプリのcompileSdkVersionを変えずに依存関係先のAARを変更したい場合は、dependenciesの依存関係先のAARのバージョンを落としてやればそれでも動く気がするが、めんどくさいので試していない。。。