Cannot add a configuration with name 'classpath' as a configuration with that name already exists (intermittent plugin-gradle concurrency bug)

Hi, we just had a spurious error on our jenkins after upgrading our spotless gradle plugin to 3.18 due to “org.gradle.api.InvalidUserDataException: Cannot add a configuration with name ‘classpath’ as a configuration with that name already exists.” This is for a multiproject build with parallel execution and it seems that gradle tries to create the classpath configuration multiple times in DefaultScriptHandler. Seeing as there are no locks in this code, I’m guessing that defineConfiguration() is not meant to be called in parallel but somehow it is being called that way.

Also the error message printed to the log about missing repos is a bit confusing due to GradleProvisioner catching Exception and printing a error message that’s better suited for catching ResolveException. I first troubleshooting thought was to go to our artifactory and check our logs (it sent the files correctly).

Gradle 5.2.1, Spotless gradle plugin 3.18, Ubuntu 16.04 docker container.

buildSrc/build.gradle
=====================

repositories {
  maven {
    url 'https://ourartifactory.stuff/mvn'
    credentials {
      username = artifactory_user
      password = artifactory_password
    }
  }
}
dependencies {
  compile "com.diffplug.spotless:spotless-plugin-gradle:3.18.0" // Use of buildSrc to infer repositories/dependencies to all build scripts
}


build.gradle
============
allprojects {
  pluginManager.withPlugin('java') {
    apply plugin: "com.diffplug.gradle.spotless"
    spotless {
      // See https://github.com/diffplug/spotless/tree/master/plugin-gradle for configuration
      java {
        target 'src/**/*.java' // Only format checked in code, not generated sources        
        removeUnusedImports() // removes any unused imports
        eclipse('4.9.0').configFile "$rootDir/utils/.settings/org.eclipse.jdt.core.prefs"
      }
    }
    tasks.withType(JavaCompile)*.dependsOn 'spotlessApply'    
  }
}

07:42:47  > Task :SubProj1:spotlessJava
07:42:47  You probably need to add a repository containing the '[com.google.googlejavaformat:google-java-format:1.7]' artifact in the 'build.gradle' of your root project.
07:42:47  E.g.: 'buildscript { repositories { mavenCentral() }}'
07:42:47  Note that included buildscripts (using 'apply from') do not share their buildscript repositories with the underlying project.
07:42:47  You have to specify the missing repository explicitly in the buildscript of the root project.
07:42:47  
07:42:47  org.gradle.api.InvalidUserDataException: Cannot add a configuration with name 'classpath' as a configuration with that name already exists.
07:42:47  	at org.gradle.api.internal.DefaultNamedDomainObjectCollection.assertCanAdd(DefaultNamedDomainObjectCollection.java:212)
07:42:47  	at org.gradle.api.internal.AbstractNamedDomainObjectContainer.create(AbstractNamedDomainObjectContainer.java:93)
07:42:47  	at org.gradle.api.internal.AbstractValidatingNamedDomainObjectContainer.create(AbstractValidatingNamedDomainObjectContainer.java:46)
07:42:47  	at org.gradle.api.internal.AbstractNamedDomainObjectContainer.create(AbstractNamedDomainObjectContainer.java:75)
07:42:47  	at org.gradle.api.internal.initialization.DefaultScriptHandler.defineConfiguration(DefaultScriptHandler.java:111)
07:42:47  	at org.gradle.api.internal.initialization.DefaultScriptHandler.getConfigurations(DefaultScriptHandler.java:101)
07:42:47  	at com.diffplug.gradle.spotless.GradleProvisioner.lambda$fromProject$1(GradleProvisioner.java:40)
07:42:47  	at com.diffplug.spotless.JarState.provisionWithTransitives(JarState.java:87)
07:42:47  	at com.diffplug.spotless.JarState.from(JarState.java:76)
07:42:47  	at com.diffplug.spotless.JarState.from(JarState.java:71)
07:42:47  	at com.diffplug.spotless.java.GoogleJavaFormatStep$State.<init>(GoogleJavaFormatStep.java:99)
07:42:47  	at com.diffplug.spotless.java.GoogleJavaFormatStep$State.<init>(GoogleJavaFormatStep.java:95)
07:42:47  	at com.diffplug.spotless.java.RemoveUnusedImportsStep.lambda$create$0(RemoveUnusedImportsStep.java:33)
07:42:47  	at com.diffplug.spotless.FormatterStepImpl.calculateState(FormatterStepImpl.java:56)
07:42:47  	at com.diffplug.spotless.LazyForwardingEquality.state(LazyForwardingEquality.java:56)
07:42:47  	at com.diffplug.spotless.LazyForwardingEquality.writeObject(LazyForwardingEquality.java:68)
07:42:47  	at sun.reflect.GeneratedMethodAccessor535.invoke(Unknown Source)
07:42:47  	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
07:42:47  	at java.lang.reflect.Method.invoke(Method.java:498)
07:42:47  	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1128)
07:42:47  	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
07:42:47  	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
07:42:47  	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
07:42:47  	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
07:42:47  	at org.gradle.internal.snapshot.impl.DefaultValueSnapshotter.serialize(DefaultValueSnapshotter.java:180)
07:42:47  	at org.gradle.internal.snapshot.impl.DefaultValueSnapshotter.processValue(DefaultValueSnapshotter.java:172)
07:42:47  	at org.gradle.internal.snapshot.impl.DefaultValueSnapshotter.snapshot(DefaultValueSnapshotter.java:59)
07:42:47  	at org.gradle.internal.snapshot.ValueSnapshotStrategy.snapshot(ValueSnapshotStrategy.java:30)
07:42:47  	at org.gradle.internal.snapshot.impl.DefaultValueSnapshotter.processValue(DefaultValueSnapshotter.java:99)
07:42:47  	at org.gradle.internal.snapshot.impl.DefaultValueSnapshotter.snapshot(DefaultValueSnapshotter.java:59)
07:42:47  	at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionStateTaskExecuter.snapshotTaskInputProperties(ResolveBeforeExecutionStateTaskExecuter.java:124)
07:42:47  	at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionStateTaskExecuter.createExecutionState(ResolveBeforeExecutionStateTaskExecuter.java:90)
07:42:47  	at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionStateTaskExecuter.execute(ResolveBeforeExecutionStateTaskExecuter.java:72)
07:42:47  	at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
07:42:47  	at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:109)
07:42:47  	at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionOutputsTaskExecuter.execute(ResolveBeforeExecutionOutputsTaskExecuter.java:67)
07:42:47  	at org.gradle.api.internal.tasks.execution.ResolveAfterPreviousExecutionStateTaskExecuter.execute(ResolveAfterPreviousExecutionStateTaskExecuter.java:46)
07:42:47  	at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:93)
07:42:47  	at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:45)
07:42:47  	at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:94)
07:42:47  	at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
07:42:47  	at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:56)
07:42:47  	at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
07:42:47  	at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:63)
07:42:47  	at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:49)
07:42:47  	at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:46)
07:42:47  	at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
07:42:47  	at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
07:42:47  	at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
07:42:47  	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
07:42:47  	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
07:42:47  	at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
07:42:47  	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
07:42:47  	at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:46)
07:42:47  	at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:43)
07:42:47  	at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:355)
07:42:47  	at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:343)
07:42:47  	at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:336)
07:42:47  	at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:322)
07:42:47  	at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:134)
07:42:47  	at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:129)
07:42:47  	at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:202)
07:42:47  	at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:193)
07:42:47  	at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:129)
07:42:47  	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
07:42:47  	at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
07:42:47  	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
07:42:47  	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
07:42:47  	at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
07:42:47  	at java.lang.Thread.run(Thread.java:748)
07:42:47  

[vlsi]

What is unsafe about it?

It seems to defeat Gradle Build Scan as well (however they seem to agree to fix that):

https://discuss.gradle.org/t/your-build-scan-could-not-be-displayed-what-does-this-mean/33302/10

[uklance]

I’ll not be contributing such a fix so I think your duct tape wins. I’d argue

synchronized (project.getRootProject()) {...} 

Is slightly better than

synchronized (GradleProvisioner.class) {...}