Android Studio 3.3: New Gradle Sync is not supported due to containing Kotlin modules (invalid type code: 68)

Question

in a java-kotlin hybrid using Android Studio 3.3 and above, I get an invalid type code: 68 error message. When using gradle 5.1 and above I get an additional message saying "New Gradle Sync is not supported due to containing Kotlin modules"

How to reproduce in android studio 3.3:

1) create a new android project in java with a blank activity

2) create a kotlin class file

3) click on the configure kotlin button to add the kotlin plugins and library to the project

4) sync gradle

My projects used to run fine on the previous Android Studio stable release (3.2.1)

full stack trace:

org.gradle.tooling.GradleConnectionException: Could not run build action using Gradle distribution 'https://services.gradle.org/distributions/gradle-5.1.1-all.zip'.
    at org.gradle.tooling.internal.consumer.ExceptionTransformer.transform(ExceptionTransformer.java:55)
    at org.gradle.tooling.internal.consumer.ExceptionTransformer.transform(ExceptionTransformer.java:29)
    at org.gradle.tooling.internal.consumer.ResultHandlerAdapter.onFailure(ResultHandlerAdapter.java:41)
    at org.gradle.tooling.internal.consumer.async.DefaultAsyncConsumerActionExecutor$1$1.run(DefaultAsyncConsumerActionExecutor.java:57)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
    at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
    at java.lang.Thread.run(Thread.java:745)
    at org.gradle.tooling.internal.consumer.BlockingResultHandler.getResult(BlockingResultHandler.java:46)
    at org.gradle.tooling.internal.consumer.DefaultBuildActionExecuter.run(DefaultBuildActionExecuter.java:65)
    at com.android.tools.idea.gradle.project.sync.ng.SyncExecutor.doFetchModels(SyncExecutor.java:255)
    at com.android.tools.idea.gradle.project.sync.ng.SyncExecutor.executeFullSync(SyncExecutor.java:239)
    at com.android.tools.idea.gradle.project.sync.ng.SyncExecutor.syncProject(SyncExecutor.java:197)
    at com.android.tools.idea.gradle.project.sync.ng.SyncExecutor.lambda$syncProject$1(SyncExecutor.java:134)
    at org.jetbrains.plugins.gradle.service.execution.GradleExecutionHelper.execute(GradleExecutionHelper.java:209)
    at com.android.tools.idea.gradle.project.sync.ng.SyncExecutor.syncProject(SyncExecutor.java:139)
    at com.android.tools.idea.gradle.project.sync.ng.NewGradleSync.sync(NewGradleSync.java:185)
    at com.android.tools.idea.gradle.project.sync.ng.NewGradleSync.access$000(NewGradleSync.java:59)
    at com.android.tools.idea.gradle.project.sync.ng.NewGradleSync$2.run(NewGradleSync.java:151)
    at com.intellij.openapi.progress.impl.CoreProgressManager$TaskRunnable.run(CoreProgressManager.java:736)
    at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$1(CoreProgressManager.java:157)
    at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:580)
    at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:525)
    at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:85)
    at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:144)
    at com.intellij.openapi.progress.impl.CoreProgressManager$4.run(CoreProgressManager.java:395)
    at com.intellij.openapi.application.impl.ApplicationImpl$1.run(ApplicationImpl.java:314)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.gradle.api.UncheckedIOException: java.io.StreamCorruptedException: invalid type code: 68
    at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:61)
    at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:41)
    at org.gradle.tooling.internal.provider.serialization.PayloadSerializer.deserialize(PayloadSerializer.java:76)
    at org.gradle.tooling.internal.provider.ProviderConnection.throwFailure(ProviderConnection.java:205)
    at org.gradle.tooling.internal.provider.ProviderConnection.run(ProviderConnection.java:193)
    at org.gradle.tooling.internal.provider.ProviderConnection.runClientAction(ProviderConnection.java:153)
    at org.gradle.tooling.internal.provider.ProviderConnection.run(ProviderConnection.java:143)
    at org.gradle.tooling.internal.provider.DefaultConnection.run(DefaultConnection.java:222)
    at org.gradle.tooling.internal.consumer.connection.ParametrizedActionRunner.execute(ParametrizedActionRunner.java:36)
    at org.gradle.tooling.internal.consumer.connection.CancellableActionRunner.run(CancellableActionRunner.java:51)
    at org.gradle.tooling.internal.consumer.connection.AbstractConsumerConnection.run(AbstractConsumerConnection.java:63)
    at org.gradle.tooling.internal.consumer.connection.ParameterValidatingConsumerConnection.run(ParameterValidatingConsumerConnection.java:54)
    at org.gradle.tooling.internal.consumer.DefaultBuildActionExecuter$1.run(DefaultBuildActionExecuter.java:76)
    at org.gradle.tooling.internal.consumer.connection.LazyConsumerActionExecutor.run(LazyConsumerActionExecutor.java:84)
    at org.gradle.tooling.internal.consumer.connection.CancellableConsumerActionExecutor.run(CancellableConsumerActionExecutor.java:45)
    at org.gradle.tooling.internal.consumer.connection.ProgressLoggingConsumerActionExecutor.run(ProgressLoggingConsumerActionExecutor.java:58)
    at org.gradle.tooling.internal.consumer.connection.RethrowingErrorsConsumerActionExecutor.run(RethrowingErrorsConsumerActionExecutor.java:38)
    at org.gradle.tooling.internal.consumer.async.DefaultAsyncConsumerActionExecutor$1$1.run(DefaultAsyncConsumerActionExecutor.java:55)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
    at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
    ... 1 more
Caused by: java.io.StreamCorruptedException: invalid type code: 68
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1563)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2231)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2155)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2013)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1535)
    at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1919)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1529)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2231)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2155)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2013)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1535)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2231)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2155)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2013)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1535)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2231)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2155)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2013)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1535)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:422)
    at org.gradle.tooling.internal.provider.serialization.PayloadSerializer.deserialize(PayloadSerializer.java:74)
    ... 21 more

Answer 1

Change Preferences > Experimental > Only sync the active variant (uncheck this).

Alternatively, to edit the corresponding setting manually in your project files: Try setting not.eligible.for.single.variant.sync to true in .idea/workspace.xml

You can either edit the XML directly as shown below or use the Settings UI of IntelliJ:

  <component name="PropertiesComponent">
    <property name="not.eligible.for.single.variant.sync" value="true" />
  </component>

This is because single variant sync is not supported in Kotlin

Note: This optimization fully supports projects that include Java and C++ languages, and has some support for Kotlin. When enabling the optimization for projects with Kotlin content, Gradle sync falls back to using full variants internally.

https://developer.android.com/studio/build/optimize-your-build#single_variant_sync

As to why Gradle is failing to fall back to full variant sync automatically, or why Android Studio isn't automatically setting this flag for you, I have no idea.