Using a kotlin closure for `custom` step no longer works in Gradle plugin

Open

#2,387 opened on Jan 7, 2025 3 comments 2 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty: 4/5
Estimated time: 3-5 days
Newbie friendliness: 32/100

Issue type: Bug
Clarity: Mostly clear
Activity status: Stale
Tech stack: java, kotlin
Domain: build-system

Research direction

Reproduce the failure with the Gradle 8.12 custom step and run spotlessCheck or spotlessApply. Start at the custom formatter-step handling and the serialization path named in FormatterStepEqualityOnStateSerialization; add regression coverage for the Kotlin closure and confirm it no longer raises NotSerializableException.

Written by the indexing model from the issue text.

Description

bug

summary of problem

Using a kotlin closure for custom step no longer works in Gradle plugin

Gradle or Maven version

Gradle 8.12

spotless version

7.0.0 and 7.0.1

operating system and version

Mac/latest

copy-paste your full Spotless configuration block(s), and a link to a public git repo that reproduces the problem if possible

java {
    custom("Refuse wildcard imports") {
        if (it.contains("*;\n")) {
            throw GradleException("No wildcard imports allowed.")
        }
        it
    }
}

copy-paste the full content of any console errors emitted by gradlew spotless[Apply/Check] --stacktrace

> Task :spotlessJava FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':spotlessJava'.
> java.io.NotSerializableException: REDACTED

* Try:
> Run with --info or --debug option to get more log output.
> Get more help at https://help.gradle.org.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':spotlessJava'.
        at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:38)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:42)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:331)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:318)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.lambda$execute$0(DefaultTaskExecutionGraph.java:314)
        at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:85)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:314)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:303)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:459)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:376)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
        at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:48)
Caused by: com.diffplug.spotless.ThrowingEx$WrappedAsRuntimeException: java.io.NotSerializableException: Spotless_init_gradle$1$1$2$1$1$1
        at com.diffplug.spotless.ThrowingEx.asRuntime(ThrowingEx.java:95)
        at com.diffplug.spotless.LazyForwardingEquality.toBytes(LazyForwardingEquality.java:111)
        at com.diffplug.spotless.FormatterStepEqualityOnStateSerialization.lambda$serializedState$0(FormatterStepEqualityOnStateSerialization.java:93)
        at com.diffplug.spotless.ThrowingEx.get(ThrowingEx.java:67)
        at com.diffplug.spotless.FormatterStepEqualityOnStateSerialization.serializedState(FormatterStepEqualityOnStateSerialization.java:93)
        at com.diffplug.spotless.FormatterStepEqualityOnStateSerialization.hashCode(FormatterStepEqualityOnStateSerialization.java:73)
        at com.diffplug.spotless.FormatterStepSerializationRoundtrip$HackClone.hashCode(FormatterStepSerializationRoundtrip.java:137)
        at com.diffplug.spotless.ConfigurationCacheHackList.hashCode(ConfigurationCacheHackList.java:148)
        at org.gradle.internal.execution.impl.DefaultInputFingerprinter$InputCollectingVisitor.visitInputProperty(DefaultInputFingerprinter.java:114)
        at org.gradle.api.internal.tasks.execution.TaskExecution.visitRegularInputs(TaskExecution.java:315)
        at org.gradle.internal.execution.impl.DefaultInputFingerprinter.fingerprintInputProperties(DefaultInputFingerprinter.java:63)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.captureExecutionStateWithOutputs(AbstractCaptureStateBeforeExecutionStep.java:109)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.lambda$captureExecutionState$0(AbstractCaptureStateBeforeExecutionStep.java:74)
        at org.gradle.internal.execution.steps.BuildOperationStep$1.call(BuildOperationStep.java:37)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
        at org.gradle.internal.execution.steps.BuildOperationStep.operation(BuildOperationStep.java:34)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.captureExecutionState(AbstractCaptureStateBeforeExecutionStep.java:69)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.execute(AbstractCaptureStateBeforeExecutionStep.java:62)
        at org.gradle.internal.execution.steps.AbstractCaptureStateBeforeExecutionStep.execute(AbstractCaptureStateBeforeExecutionStep.java:43)
        at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.executeWithNonEmptySources(AbstractSkipEmptyWorkStep.java:125)
        at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.execute(AbstractSkipEmptyWorkStep.java:56)
        at org.gradle.internal.execution.steps.AbstractSkipEmptyWorkStep.execute(AbstractSkipEmptyWorkStep.java:36)
        at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsStartedStep.execute(MarkSnapshottingInputsStartedStep.java:38)
        at org.gradle.internal.execution.steps.LoadPreviousExecutionStateStep.execute(LoadPreviousExecutionStateStep.java:36)
        at org.gradle.internal.execution.steps.LoadPreviousExecutionStateStep.execute(LoadPreviousExecutionStateStep.java:23)
        at org.gradle.internal.execution.steps.HandleStaleOutputsStep.execute(HandleStaleOutputsStep.java:75)
        at org.gradle.internal.execution.steps.HandleStaleOutputsStep.execute(HandleStaleOutputsStep.java:41)
        at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.lambda$execute$0(AssignMutableWorkspaceStep.java:35)
        at org.gradle.api.internal.tasks.execution.TaskExecution$4.withWorkspace(TaskExecution.java:289)
        at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.execute(AssignMutableWorkspaceStep.java:31)
        at org.gradle.internal.execution.steps.AssignMutableWorkspaceStep.execute(AssignMutableWorkspaceStep.java:22)
        at org.gradle.internal.execution.steps.ChoosePipelineStep.execute(ChoosePipelineStep.java:40)
        at org.gradle.internal.execution.steps.ChoosePipelineStep.execute(ChoosePipelineStep.java:23)
        at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.lambda$execute$2(ExecuteWorkBuildOperationFiringStep.java:67)
        at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.execute(ExecuteWorkBuildOperationFiringStep.java:67)
        at org.gradle.internal.execution.steps.ExecuteWorkBuildOperationFiringStep.execute(ExecuteWorkBuildOperationFiringStep.java:39)
        at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:46)
        at org.gradle.internal.execution.steps.IdentityCacheStep.execute(IdentityCacheStep.java:34)
        at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:48)
        at org.gradle.internal.execution.steps.IdentifyStep.execute(IdentifyStep.java:35)
        at org.gradle.internal.execution.impl.DefaultExecutionEngine$1.execute(DefaultExecutionEngine.java:61)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:127)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:116)
        at org.gradle.api.internal.tasks.execution.ProblemsTaskPathTrackingTaskExecuter.execute(ProblemsTaskPathTrackingTaskExecuter.java:40)
        at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:51)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
        at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:74)
        at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:209)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:204)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:66)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$2.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:166)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:59)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:53)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:42)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:331)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:318)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.lambda$execute$0(DefaultTaskExecutionGraph.java:314)
        at org.gradle.internal.operations.CurrentBuildOperationRef.with(CurrentBuildOperationRef.java:85)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:314)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:303)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:459)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:376)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
        at org.gradle.internal.concurrent.AbstractManagedExecutor$1.run(AbstractManagedExecutor.java:48)
Caused by: java.io.NotSerializableException: REDACTED
        at com.diffplug.spotless.FormatterStepSerializationRoundtrip.writeObject(FormatterStepSerializationRoundtrip.java:81)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at com.diffplug.spotless.FormatterStepSerializationRoundtrip$HackClone.writeObject(FormatterStepSerializationRoundtrip.java:118)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at com.diffplug.spotless.ConfigurationCacheHackList.writeObject(ConfigurationCacheHackList.java:76)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
        at com.diffplug.spotless.LazyForwardingEquality.toBytes(LazyForwardingEquality.java:109)
        ... 75 more


BUILD FAILED in 1s
11 actionable tasks: 1 executed, 10 up-to-date

Dominant language: Java
Stars: 5.7k
Forks: 560
Avg merge: 1d 13h
Merged PRs (30d): 43

Contributor guide

Open the contributing guide

First steps

Read the whole issue, then the project's contributing guide.
Comment on the issue to say you are picking it up — it saves two people doing the same work.
Fork the repository and make your change on a branch.
Open a pull request that references the issue number.

Similar issues

Resize volume API validation errors are not displayed in the UI Open

bug

Difficulty 1/5 Under an hour Newbie friendliness 90/100

apache/cloudstack#14222 · Opened Sep 22, 2026
[BUG]茶杯方块在取茶时会引发崩溃 Open

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

KaleidoscopeMods/KaleidoscopeCookery#218 · Opened Sep 22, 2026
Cannot differ own consent and managed consents in My Consents view and detailed consent view. Open

1.0.0-alpha2 Type/Improvement

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

wso2/dpdp-accelerator#272 · Opened Sep 22, 2026
[Bug] An aborted AI stream clears the duplicate-send guard of a newer conversation Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 88/100

apache/rocketmq-dashboard#4860 · 1 comment · Opened Sep 22, 2026
Document Hot Rod migration version compatibility for Data Grid 8.6 Open

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

infinispan/infinispan#18150 · Opened Sep 21, 2026

More Java issues