Problem
If you’re getting the error when running React Native or Expo for Android:
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:checkDebugDuplicateClasses'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.CheckDuplicatesRunnable
> Duplicate class android.support.v4.app.INotificationSideChannel found in modules core-1.13.1.aar -> core-1.13.1-runtime (androidx.core:core:1.13.1) and support-compat-26.1.0.aar -> support-compat-26.1.0-runtime (com.android.support:support-compat:26.1.0)
Go to the documentation to learn how to <a href="d.android.com/r/tools/classpath-sync-errors">Fix dependency resolution errors</a>.
* 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 13s
Error: ./android/gradlew app:assembleDebug -x lint -x test --configure-on-demand --build-cache -PreactNativeDevServerPort=8081 -PreactNativeArchitectures=arm64-v8a exited with non-zero code: 1
The build fails because there are duplicated classes in 2+ dependencies and the compiler doesn’t know which one to use during runtime.
This happens when you’re importing modules that carry their own required libraries, which leads to transitive dependencies.
Solution
The solution is to exclude duplicated classes from libraries in android/app/build.gradle:
apply plugin: "com.android.application"
// ...
android {
// ...
configurations {
all {
exclude group: "com.android.support"
exclude module: "appcompat-v7"
exclude module: "support-v4"
}
}
}