Build produces Gradle deprecation warnings for sourceSets.main.output.classesDirs

[alpar-t]

Here's one Example, but there are others throughout the build:

./gradlew x-pack:plugin:monitoring:build --dry-run -Dorg.gradle.warning.mode=all --warning-mode=all --stacktrace

Gradle now uses separate output directories for each JVM language, but this build assumes a single directory for all classes from a source set. This behaviour has been deprecated and is scheduled to be removed in Gradle 5.0
	at org.gradle.api.internal.tasks.DefaultSourceSetOutput.getClassesDir(DefaultSourceSetOutput.java:81)
	at org.gradle.api.internal.tasks.DefaultSourceSetOutput_Decorated.getClassesDir(Unknown Source)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
	at org.codehaus.groovy.runtime.metaclass.MultipleSetterProperty.getProperty(MultipleSetterProperty.java:49)
	at org.gradle.internal.metaobject.BeanDynamicObject$MetaClassAdapter.getProperty(BeanDynamicObject.java:228)
	at org.gradle.internal.metaobject.BeanDynamicObject.tryGetProperty(BeanDynamicObject.java:171)
	at org.gradle.internal.metaobject.CompositeDynamicObject.tryGetProperty(CompositeDynamicObject.java:55)
	at org.gradle.internal.metaobject.AbstractDynamicObject.getProperty(AbstractDynamicObject.java:59)
	at org.gradle.api.internal.tasks.DefaultSourceSetOutput_Decorated.getProperty(Unknown Source)
	at org.codehaus.groovy.runtime.callsite.PogoGetPropertySite.getProperty(PogoGetPropertySite.java:50)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callGetProperty(AbstractCallSite.java:296)
	at org.elasticsearch.gradle.precommit.NamingConventionsTask$_closure1.doCall(NamingConventionsTask.groovy:88)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
	at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
	at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:294)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1022)
	at groovy.lang.Closure.call(Closure.java:414)
	at groovy.lang.Closure.call(Closure.java:430)
	at org.gradle.api.specs.internal.ClosureSpec.isSatisfiedBy(ClosureSpec.java:32)
	at org.gradle.api.specs.AndSpec.isSatisfiedBy(AndSpec.java:47)
	at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:42)
	at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
	at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
	at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:256)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:317)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:309)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:185)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:97)
	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
	at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:249)
	at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:238)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98)
	at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:663)
	at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:596)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98)
	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
	at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1135)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
	at java.base/java.lang.Thread.run(Thread.java:844)

[elasticmachine]

Pinging @elastic/es-core-infra

[DaveCTurner]

Relates #27250