[Error] Room - cannot find implementation for 패키지명.

cannot find implementation for [package_name]

Caused by: java.lang.RuntimeException: cannot find implementation for com.jikyunghee.mobile.android.myapplication.learn.mvvm.db.ContactDatabase. ContactDatabase_Impl does not exist

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Error!

    //room
    implementation 'androidx.room:room-runtime:2.2.5'

해결! - annotationProcessor을 추가해준다!

    //room
    implementation 'androidx.room:room-runtime:2.2.5'
    annotationProcessor 'androidx.room:room-compiler:2.2.5'

annotationProcessor: 컴파일 시점으로 코드를 생성

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참고

https://cchoimin.tistory.com/entry/Gradle-annotationProcessor