The number of method references in a .dex file cannot exceed 64K

I've been maintaining a React Native app for several years now, I'm really happy with my stack as I can quickly add new features and iterate for Android an iOS.

However, a few days ago I migrated to Sentry as my third-party service to keep track of crashes and errors in the app. Everything went well on iOS after installation, however, on Android, I started getting errors when trying to build the app.

D8: Cannot fit requested classes in a single dex file (# fields: 67142 > 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:131)
    at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:118)
    at com.android.build.gradle.internal.transforms.DexMergerTransformCallable.call(DexMergerTransformCallable.java:102)
    at com.android.build.gradle.internal.tasks.DexMergingTaskRunnable.run(DexMergingTask.kt:444)
    at com.android.build.gradle.internal.tasks.Workers$ActionFacade.run(Workers.kt:335)
    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:66)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1$1.create(NoIsolationWorkerFactory.java:62)
    at org.gradle.internal.classloader.ClassLoaderUtils.executeInClassloader(ClassLoaderUtils.java:98)
    at org.gradle.workers.internal.NoIsolationWorkerFactory$1.lambda$execute$0(NoIsolationWorkerFactory.java:62)
    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:416)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
    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$1.execute(NoIsolationWorkerFactory.java:59)
    at org.gradle.workers.internal.DefaultWorkerExecutor.lambda$submitWork$2(DefaultWorkerExecutor.java:198)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at org.gradle.internal.work.DefaultConditionalExecutionQueue$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$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
    at java.lang.Thread.run(Thread.java:748)
Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete
    at com.android.tools.r8.utils.t.a(:55)
    at com.android.tools.r8.D8.run(:11)
    at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:116)
    ... 33 more
Caused by: com.android.tools.r8.utils.AbortException: Error: null, Cannot fit requested classes in a single dex file (# fields: 67142 > 65536)
    at com.android.tools.r8.utils.Reporter.a(:21)
    at com.android.tools.r8.utils.Reporter.a(:7)
    at com.android.tools.r8.dex.VirtualFile.a(:33)
    at com.android.tools.r8.dex.VirtualFile$h.a(:5)
    at com.android.tools.r8.dex.ApplicationWriter.a(:13)
    at com.android.tools.r8.dex.ApplicationWriter.write(:35)
    at com.android.tools.r8.D8.d(:44)
    at com.android.tools.r8.D8.b(:1)
    at com.android.tools.r8.utils.t.a(:23)
    ... 35 more


FAILURE: Build failed with an exception.

It's the first time I see an error like this, so after searching for a few minutes I found out the issue was not related to Sentry at all, but it's a limitation with the Android architecture.

When your app and the libraries it references exceed 65,536 methods, you encounter a build error that indicates your app has reached the limit of the Android build architecture

So basically anyone can reach to this limitation! Given that I added a new dependency my app got to this point.

The fix is simple, however the recommendation is to avoid getting to this limit by removing dependencies, but if you really can't do that you can bypass this limitation by opening the android/app/build.gradle file and adding these two lines:

android {
    defaultConfig {
        ...
        multiDexEnabled true
    }
    ...
}

dependencies {
  implementation 'com.android.support:multidex:1.0.3'
}

After that try to build again and your application should build without any issues 🎉