I've had builds fail recently due to duplicate meta-data entries. The most recent being https://ge.spring.io/s/p5yonxuszztr2/failure#1.

It looks like it might be possible to have duplicate entries in org.springframework.boot.configurationprocessor.metadata.ConfigurationMetadata, but I'm not sure how/why this happens. I wonder if the flattenValues method needs reworking.

Comment From: philwebb

@snicoll Can you remember why ConfigurationMetadata uses Map<String, List<ItemMetadata>> items and not Map<String, ItemMetadata> items?

Comment From: snicoll

You may have more than one source for a key. A concrete example is additional metadata where you define the key again to provide a description (or a more fined tuned type).

Having said that, I had a look to the build scan and if I understood the failure right, this does not seem to be related to the annotation processor but rather the documentation plugin, i.e.

Caused by: java.lang.IllegalStateException: Duplicate key ConfigurationProperty [name=spring.devtools.remote.context-path, type=java.lang.String]
at org.springframework.boot.build.context.properties.ConfigurationProperties.fromFiles(ConfigurationProperties.java:70)
at org.springframework.boot.build.context.properties.ConfigurationMetadataDocumentWriter.writeDocument(ConfigurationMetadataDocumentWriter.java:46) |  
at org.springframework.boot.build.context.properties.DocumentConfigurationProperties.documentConfigurationProperties(DocumentConfigurationProperties.java:99)

Or am I looking at the wrong stacktrace?

Comment From: philwebb

The documentation plugin ends up failing because there are two entries in the json. I had one with and one without a description. I had it fail again, but adding annoyingly debugging to the processor made it go away again. I certainly seems to be cache related.

Comment From: philwebb

Here's some debug output showing that MetadataCollector.add is only called once with the key.

I added this to MetadataCollector.add:

        if ("spring.devtools.remote.context-path".equals(metadata.getName())) {
            new RuntimeException().printStackTrace();
        }
./gradlew build publishToMavenLocal -x :spring-boot-tests:spring-boot-integration-tests:spring-boot-launch-script-tests:intTest                                                                                                                 ✭ ✱

> Task :spring-boot-project:spring-boot-devtools:compileJava
java.lang.RuntimeException
        at org.springframework.boot.configurationprocessor.MetadataCollector.add(MetadataCollector.java:77)
        at org.springframework.boot.configurationprocessor.ConfigurationMetadataAnnotationProcessor.lambda$processTypeElement$0(ConfigurationMetadataAnnotationProcessor.java:231)
        at java.util.Iterator.forEachRemaining(Iterator.java:116)
        at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
        at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:647)
        at org.springframework.boot.configurationprocessor.ConfigurationMetadataAnnotationProcessor.processTypeElement(ConfigurationMetadataAnnotationProcessor.java:230)
        at org.springframework.boot.configurationprocessor.ConfigurationMetadataAnnotationProcessor.lambda$processTypeElement$0(ConfigurationMetadataAnnotationProcessor.java:236)
        at java.util.Iterator.forEachRemaining(Iterator.java:116)
        at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
        at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:647)
        at org.springframework.boot.configurationprocessor.ConfigurationMetadataAnnotationProcessor.processTypeElement(ConfigurationMetadataAnnotationProcessor.java:230)
        at org.springframework.boot.configurationprocessor.ConfigurationMetadataAnnotationProcessor.processAnnotatedTypeElement(ConfigurationMetadataAnnotationProcessor.java:202)
        at org.springframework.boot.configurationprocessor.ConfigurationMetadataAnnotationProcessor.processElement(ConfigurationMetadataAnnotationProcessor.java:187)
        at org.springframework.boot.configurationprocessor.ConfigurationMetadataAnnotationProcessor.process(ConfigurationMetadataAnnotationProcessor.java:151)
        at org.gradle.api.internal.tasks.compile.processing.DelegatingProcessor.process(DelegatingProcessor.java:62)
        at org.gradle.api.internal.tasks.compile.processing.AggregatingProcessor.process(AggregatingProcessor.java:50)
        at org.gradle.api.internal.tasks.compile.processing.DelegatingProcessor.process(DelegatingProcessor.java:62)
        at org.gradle.api.internal.tasks.compile.processing.TimeTrackingProcessor.access$401(TimeTrackingProcessor.java:37)
        at org.gradle.api.internal.tasks.compile.processing.TimeTrackingProcessor$5.create(TimeTrackingProcessor.java:99)
        at org.gradle.api.internal.tasks.compile.processing.TimeTrackingProcessor$5.create(TimeTrackingProcessor.java:96)
        at org.gradle.api.internal.tasks.compile.processing.TimeTrackingProcessor.track(TimeTrackingProcessor.java:117)
        at org.gradle.api.internal.tasks.compile.processing.TimeTrackingProcessor.process(TimeTrackingProcessor.java:96)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:802)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:713)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment.access$1800(JavacProcessingEnvironment.java:91)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1043)
        at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1184)
        at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1170)
        at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:856)
        at com.sun.tools.javac.main.Main.compile(Main.java:523)
        at com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:129)
        at com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:138)
        at org.gradle.internal.compiler.java.IncrementalCompileTask.call(IncrementalCompileTask.java:74)
        at org.gradle.api.internal.tasks.compile.AnnotationProcessingCompileTask.call(AnnotationProcessingCompileTask.java:94)
        at org.gradle.api.internal.tasks.compile.ResourceCleaningCompilationTask.call(ResourceCleaningCompilationTask.java:57)
        at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:55)
        at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:40)
        at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:97)
        at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:51)
        at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:37)
        at org.gradle.api.internal.tasks.compile.AnnotationProcessorDiscoveringCompiler.execute(AnnotationProcessorDiscoveringCompiler.java:51)
        at org.gradle.api.internal.tasks.compile.AnnotationProcessorDiscoveringCompiler.execute(AnnotationProcessorDiscoveringCompiler.java:37)
        at org.gradle.api.internal.tasks.compile.ModuleApplicationNameWritingCompiler.execute(ModuleApplicationNameWritingCompiler.java:46)
        at org.gradle.api.internal.tasks.compile.ModuleApplicationNameWritingCompiler.execute(ModuleApplicationNameWritingCompiler.java:36)
        at org.gradle.api.internal.tasks.compile.incremental.SelectiveCompiler.execute(SelectiveCompiler.java:82)
        at org.gradle.api.internal.tasks.compile.incremental.SelectiveCompiler.execute(SelectiveCompiler.java:37)
        at org.gradle.api.internal.tasks.compile.incremental.IncrementalResultStoringCompiler.execute(IncrementalResultStoringCompiler.java:61)
        at org.gradle.api.internal.tasks.compile.incremental.IncrementalResultStoringCompiler.execute(IncrementalResultStoringCompiler.java:45)
        at org.gradle.api.internal.tasks.compile.CompileJavaBuildOperationReportingCompiler$2.call(CompileJavaBuildOperationReportingCompiler.java:59)
        at org.gradle.api.internal.tasks.compile.CompileJavaBuildOperationReportingCompiler$2.call(CompileJavaBuildOperationReportingCompiler.java:51)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:200)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:195)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:75)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:68)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:153)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:68)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:62)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.lambda$call$2(DefaultBuildOperationExecutor.java:76)
        at org.gradle.internal.operations.UnmanagedBuildOperationWrapper.callWithUnmanagedSupport(UnmanagedBuildOperationWrapper.java:54)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:76)
        at org.gradle.api.internal.tasks.compile.CompileJavaBuildOperationReportingCompiler.execute(CompileJavaBuildOperationReportingCompiler.java:51)
        at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:343)
        at org.gradle.api.tasks.compile.JavaCompile.performIncrementalCompilation(JavaCompile.java:237)
        at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:209)
        at sun.reflect.GeneratedMethodAccessor948.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:104)
        at org.gradle.api.internal.project.taskfactory.IncrementalInputsTaskAction.doExecute(IncrementalInputsTaskAction.java:32)
        at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:51)
        at org.gradle.api.internal.project.taskfactory.AbstractIncrementalTaskAction.execute(AbstractIncrementalTaskAction.java:25)
        at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:29)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$3.run(ExecuteActionsTaskExecuter.java:555)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:29)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$1.execute(DefaultBuildOperationRunner.java:26)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:75)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:68)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:153)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:68)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.run(DefaultBuildOperationRunner.java:56)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.lambda$run$1(DefaultBuildOperationExecutor.java:71)
        at org.gradle.internal.operations.UnmanagedBuildOperationWrapper.runWithUnmanagedSupport(UnmanagedBuildOperationWrapper.java:45)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:71)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:540)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:523)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.access$300(ExecuteActionsTaskExecuter.java:108)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.executeWithPreviousOutputFiles(ExecuteActionsTaskExecuter.java:271)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$TaskExecution.execute(ExecuteActionsTaskExecuter.java:260)
        at org.gradle.internal.execution.steps.ExecuteStep.lambda$execute$0(ExecuteStep.java:33)
        at java.util.Optional.map(Optional.java:215)
        at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:33)
        at org.gradle.internal.execution.steps.ExecuteStep.execute(ExecuteStep.java:26)
        at org.gradle.internal.execution.steps.CleanupOutputsStep.execute(CleanupOutputsStep.java:67)
        at org.gradle.internal.execution.steps.CleanupOutputsStep.execute(CleanupOutputsStep.java:36)
        at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:49)
        at org.gradle.internal.execution.steps.ResolveInputChangesStep.execute(ResolveInputChangesStep.java:34)
        at org.gradle.internal.execution.steps.CancelExecutionStep.execute(CancelExecutionStep.java:43)
        at org.gradle.internal.execution.steps.TimeoutStep.executeWithoutTimeout(TimeoutStep.java:73)
        at org.gradle.internal.execution.steps.TimeoutStep.execute(TimeoutStep.java:54)
        at org.gradle.internal.execution.steps.CreateOutputsStep.execute(CreateOutputsStep.java:44)
        at org.gradle.internal.execution.steps.SnapshotOutputsStep.execute(SnapshotOutputsStep.java:54)
        at org.gradle.internal.execution.steps.SnapshotOutputsStep.execute(SnapshotOutputsStep.java:38)
        at org.gradle.internal.execution.steps.BroadcastChangingOutputsStep.execute(BroadcastChangingOutputsStep.java:42)
        at org.gradle.internal.execution.steps.CacheStep.executeWithoutCache(CacheStep.java:159)
        at org.gradle.internal.execution.steps.CacheStep.executeAndStoreInCache(CacheStep.java:135)
        at org.gradle.internal.execution.steps.CacheStep.lambda$executeWithCache$2(CacheStep.java:112)
        at java.util.Optional.orElseGet(Optional.java:267)
        at org.gradle.internal.execution.steps.CacheStep.lambda$executeWithCache$3(CacheStep.java:112)
        at org.gradle.internal.Try$Success.map(Try.java:162)
        at org.gradle.internal.execution.steps.CacheStep.executeWithCache(CacheStep.java:81)
        at org.gradle.internal.execution.steps.CacheStep.execute(CacheStep.java:71)
        at org.gradle.internal.execution.steps.CacheStep.execute(CacheStep.java:43)
        at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:44)
        at org.gradle.internal.execution.steps.StoreExecutionStateStep.execute(StoreExecutionStateStep.java:33)
        at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:38)
        at org.gradle.internal.execution.steps.RecordOutputsStep.execute(RecordOutputsStep.java:24)
        at org.gradle.internal.execution.steps.SkipUpToDateStep.executeBecause(SkipUpToDateStep.java:92)
        at org.gradle.internal.execution.steps.SkipUpToDateStep.lambda$execute$0(SkipUpToDateStep.java:85)
        at java.util.Optional.map(Optional.java:215)
        at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:55)
        at org.gradle.internal.execution.steps.SkipUpToDateStep.execute(SkipUpToDateStep.java:39)
        at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:76)
        at org.gradle.internal.execution.steps.ResolveChangesStep.execute(ResolveChangesStep.java:37)
        at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:36)
        at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsFinishedStep.execute(MarkSnapshottingInputsFinishedStep.java:26)
        at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:94)
        at org.gradle.internal.execution.steps.ResolveCachingStateStep.execute(ResolveCachingStateStep.java:49)
        at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:79)
        at org.gradle.internal.execution.steps.CaptureStateBeforeExecutionStep.execute(CaptureStateBeforeExecutionStep.java:53)
        at org.gradle.internal.execution.steps.ValidateStep.execute(ValidateStep.java:74)
        at org.gradle.internal.execution.steps.SkipEmptyWorkStep.lambda$execute$2(SkipEmptyWorkStep.java:78)
        at java.util.Optional.orElseGet(Optional.java:267)
        at org.gradle.internal.execution.steps.SkipEmptyWorkStep.execute(SkipEmptyWorkStep.java:78)
        at org.gradle.internal.execution.steps.SkipEmptyWorkStep.execute(SkipEmptyWorkStep.java:34)
        at org.gradle.internal.execution.steps.legacy.MarkSnapshottingInputsStartedStep.execute(MarkSnapshottingInputsStartedStep.java:39)
        at org.gradle.internal.execution.steps.LoadExecutionStateStep.execute(LoadExecutionStateStep.java:40)
        at org.gradle.internal.execution.steps.LoadExecutionStateStep.execute(LoadExecutionStateStep.java:28)
        at org.gradle.internal.execution.impl.DefaultWorkExecutor.execute(DefaultWorkExecutor.java:33)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:187)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:179)
        at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:109)
        at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:62)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
        at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:56)
        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:200)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$CallableBuildOperationWorker.execute(DefaultBuildOperationRunner.java:195)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:75)
        at org.gradle.internal.operations.DefaultBuildOperationRunner$3.execute(DefaultBuildOperationRunner.java:68)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:153)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.execute(DefaultBuildOperationRunner.java:68)
        at org.gradle.internal.operations.DefaultBuildOperationRunner.call(DefaultBuildOperationRunner.java:62)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.lambda$call$2(DefaultBuildOperationExecutor.java:76)
        at org.gradle.internal.operations.UnmanagedBuildOperationWrapper.callWithUnmanagedSupport(UnmanagedBuildOperationWrapper.java:54)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:76)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:41)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:372)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:359)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:352)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:338)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.lambda$run$0(DefaultPlanExecutor.java:127)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:191)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:182)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:124)
        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)

> Task :spring-boot-project:spring-boot-actuator-autoconfigure:javadoc
javadoc: warning - Multiple sources of package comments found for package "javax.servlet"
javadoc: warning - Multiple sources of package comments found for package "javax.servlet.http"

> Task :spring-boot-project:spring-boot-docs:documentConfigurationProperties FAILED

> Task :spring-boot-project:spring-boot-autoconfigure:javadoc
[ant:checkstyle] /Users/pwebb/.gradle/caches/modules-2/files-2.1/com.samskivert/jmustache/1.15/7b3b15951d13b774c76db2f4e14d977952f8b4d8/jmustache-1.15.jar(com/samskivert/mustache/Mustache.java):319: warning: no @param for ctx
[ant:checkstyle]         VariableFetcher createFetcher (Object ctx, String name);
[ant:checkstyle]                         ^
[ant:checkstyle] /Users/pwebb/.gradle/caches/modules-2/files-2.1/com.samskivert/jmustache/1.15/7b3b15951d13b774c76db2f4e14d977952f8b4d8/jmustache-1.15.jar(com/samskivert/mustache/Mustache.java):319: warning: no @param for name
[ant:checkstyle]         VariableFetcher createFetcher (Object ctx, String name);
[ant:checkstyle]                         ^
[ant:checkstyle] /Users/pwebb/.gradle/caches/modules-2/files-2.1/com.samskivert/jmustache/1.15/7b3b15951d13b774c76db2f4e14d977952f8b4d8/jmustache-1.15.jar(com/samskivert/mustache/Mustache.java):319: warning: no @return
[ant:checkstyle]         VariableFetcher createFetcher (Object ctx, String name);
[ant:checkstyle]                         ^
[ant:checkstyle] /Users/pwebb/.gradle/caches/modules-2/files-2.1/com.samskivert/jmustache/1.15/7b3b15951d13b774c76db2f4e14d977952f8b4d8/jmustache-1.15.jar(com/samskivert/mustache/Mustache.java):306: warning: no @param for name
[ant:checkstyle]         Reader getTemplate (String name) throws Exception;
[ant:checkstyle]                ^
[ant:checkstyle] /Users/pwebb/.gradle/caches/modules-2/files-2.1/com.samskivert/jmustache/1.15/7b3b15951d13b774c76db2f4e14d977952f8b4d8/jmustache-1.15.jar(com/samskivert/mustache/Mustache.java):306: warning: no @return
[ant:checkstyle]         Reader getTemplate (String name) throws Exception;
[ant:checkstyle]                ^

> Task :spring-boot-project:spring-boot-actuator-autoconfigure:javadoc
2 warnings

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':spring-boot-project:spring-boot-docs:documentConfigurationProperties'.
> Duplicate key ConfigurationProperty [name=management.metrics.web.client.request.autotime.enabled, type=java.lang.Boolean]

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 27s
1082 actionable tasks: 261 executed, 821 up-to-date

Publishing build scan...
https://ge.spring.io/s/nlohiq52hkwe6

Comment From: wilkinsona

I don't understand the debug output. It seems to be for the addition of spring.devtools.remote.context-path yet the failure is for management.metrics.web.client.request.autotime.enabled.

It certainly seems to be cache related.

The documentConfigurationProperties task isn't catchable so it'll run whenever its inputs have changed or its output is missing. In https://ge.spring.io/s/nlohiq52hkwe6, it was management.metrics.web.client.request.autotime.enabled that was the problem and :spring-boot-project:spring-boot-actuator-autoconfigure:compileJava ran rather than coming from the cache. In https://ge.spring.io/s/bylknca2h6si2, it was spring.devtools.remote.context-path that caused the problem and :spring-boot-project:spring-boot-devtools:compileJava ran rather than coming from the cache. As far as I can tell the cache isn't the problem.

I wonder if it's a bug related to incremental compilation? Perhaps that's causing the duplicate entries to appear rather than them getting merged into one.

Comment From: philwebb

Might be related to @NestedConfigurationProperty

Comment From: snicoll

See also #10886

Comment From: philwebb

Since the cause is likely #23580 we can probably get away with fixing this in 2.4.x only

Comment From: philwebb

@wilkinsona @snicoll I've just pushed what I hope is a fix. Could you both take a quick look to make sure it's not silly.