Print path to GC root on leak (no VisualVM needed)

.gradle/buildOutputCleanup/cache.properties

@@ -0,0 +1,2 @@
+#Sun Jun 14 15:45:41 CEST 2026
+gradle.version=8.8

.tmp/jmb-all.txt

@@ -0,0 +1,195 @@
+> Task :compileJava UP-TO-DATE
+> Task :processResources NO-SOURCE
+> Task :classes UP-TO-DATE
+> Task :compileTestJava UP-TO-DATE
+> Task :processTestResources NO-SOURCE
+> Task :testClasses UP-TO-DATE
+
+> Task :test
+
+TestCleanupDetector > isRunnableCalled() PASSED
+
+TestCleanupDetector > isPhantomRefCollectable() PASSED
+
+TestJMemoryBuddy > testCreateHeapDump() STANDARD_OUT
+    Creating Heapdump at: /Users/floriankirmaier/projects/claude/JMemoryBuddy/build/heapdump_jmemb_2026-06-14_15-47-23.hprof
+
+TestJMemoryBuddy > testCreateHeapDump() PASSED
+
+TestJMemoryBuddy > simpleTest() PASSED
+
+TestJMemoryBuddy > simpleTest2() PASSED
+
+TestJMemoryBuddy > simpleTest3() PASSED
+
+TestJMemoryBuddy > multiHopPath() STANDARD_OUT
+    Creating Heapdump at: /Users/floriankirmaier/projects/claude/JMemoryBuddy/build/heapdump_jmemb_2026-06-14_15-47-25.hprof
+
+    JMemoryBuddy — path to GC root for leak: Object @7e016b900:
+      GC root [Java frame] TestJMemoryBuddy$Holder
+        ↓ TestJMemoryBuddy$Holder.field
+      Object   ← leaked
+
+    multiHopPath message: The following references should be collected: [java.lang.Object@67d18ed7]
+
+TestJMemoryBuddy > multiHopPath() PASSED
+
+TestJMemoryBuddy > negativeTest2() STANDARD_OUT
+    Creating Heapdump at: /Users/floriankirmaier/projects/claude/JMemoryBuddy/build/heapdump_jmemb_2026-06-14_15-47-25.hprof
+
+TestJMemoryBuddy > negativeTest2() STANDARD_ERROR
+    java.io.IOException: File exists
+    	at jdk.management/com.sun.management.internal.HotSpotDiagnostic.dumpHeap0(Native Method)
+    	at jdk.management/com.sun.management.internal.HotSpotDiagnostic.dumpHeap(HotSpotDiagnostic.java:70)
+    	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
+    	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
+    	at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:64)
+    	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
+    	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
+    	at java.base/sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:97)
+    	at java.management/com.sun.jmx.mbeanserver.ConvertingMethod.invokeWithOpenReturn(ConvertingMethod.java:193)
+    	at java.management/com.sun.jmx.mbeanserver.ConvertingMethod.invokeWithOpenReturn(ConvertingMethod.java:175)
+    	at java.management/com.sun.jmx.mbeanserver.MXBeanIntrospector.invokeM2(MXBeanIntrospector.java:115)
+    	at java.management/com.sun.jmx.mbeanserver.MXBeanIntrospector.invokeM2(MXBeanIntrospector.java:52)
+    	at java.management/com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:236)
+    	at java.management/com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:138)
+    	at java.management/com.sun.jmx.mbeanserver.MBeanSupport.invoke(MBeanSupport.java:252)
+    	at java.management/javax.management.StandardMBean.invoke(StandardMBean.java:405)
+    	at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:803)
+    	at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:802)
+    	at java.management/com.sun.jmx.mbeanserver.MXBeanProxy$InvokeHandler.invoke(MXBeanProxy.java:150)
+    	at java.management/com.sun.jmx.mbeanserver.MXBeanProxy.invoke(MXBeanProxy.java:167)
+    	at java.management/javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:258)
+    	at jdk.proxy2/jdk.proxy2.$Proxy12.dumpHeap(Unknown Source)
+    	at one.jpro.jmemorybuddy.JMemoryBuddy.createHeapDump(JMemoryBuddy.java:212)
+    	at one.jpro.jmemorybuddy.JMemoryBuddy.memoryTest(JMemoryBuddy.java:193)
+    	at one.jpro.jmemorybuddy.TestJMemoryBuddy.negativeTest2(TestJMemoryBuddy.java:90)
+    	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
+    	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
+    	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:767)
+    	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
+    	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
+    	at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:156)
+    	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:147)
+    	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:86)
+    	at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(InterceptingExecutableInvoker.java:103)
+    	at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.lambda$invoke$0(InterceptingExecutableInvoker.java:93)
+    	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
+    	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
+    	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
+    	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
+    	at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:92)
+    	at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:86)
+    	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$8(TestMethodTestDescriptor.java:217)
+    	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
+    	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:213)
+    	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:138)
+    	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:68)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:156)
+    	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:146)
+    	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:144)
+    	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:143)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:100)
+    	at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
+    	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:160)
+    	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:146)
+    	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:144)
+    	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:143)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:100)
+    	at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
+    	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:160)
+    	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:146)
+    	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:144)
+    	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:143)
+    	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:100)
+    	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
+    	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
+    	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
+    	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
+    	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
+    	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
+    	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
+    	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
+    	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)
+    	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)
+    	at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)
+    	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:119)
+    	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:94)
+    	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:89)
+    	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:62)
+    	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
+    	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
+    	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
+    	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
+    	at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
+    	at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
+    	at jdk.proxy1/jdk.proxy1.$Proxy2.stop(Unknown Source)
+    	at org.gradle.api.internal.tasks.testing.worker.TestWorker$3.run(TestWorker.java:193)
+    	at org.gradle.api.internal.tasks.testing.worker.TestWorker.executeAndMaintainThreadName(TestWorker.java:129)
+    	at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:100)
+    	at org.gradle.api.internal.tasks.testing.worker.TestWorker.execute(TestWorker.java:60)
+    	at org.gradle.process.internal.worker.child.ActionExecutionWorker.execute(ActionExecutionWorker.java:56)
+    	at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:119)
+    	at org.gradle.process.internal.worker.child.SystemApplicationClassLoaderWorker.call(SystemApplicationClassLoaderWorker.java:66)
+    	at worker.org.gradle.process.internal.worker.GradleWorkerMain.run(GradleWorkerMain.java:69)
+    	at worker.org.gradle.process.internal.worker.GradleWorkerMain.main(GradleWorkerMain.java:74)
+
+TestJMemoryBuddy > negativeTest2() STANDARD_OUT
+    The following references should not be collected: [[someText]]
+
+TestJMemoryBuddy > negativeTest2() PASSED
+
+TestJMemoryBuddy > testErrorMessages1() STANDARD_OUT
+    Creating Heapdump at: /Users/floriankirmaier/projects/claude/JMemoryBuddy/build/heapdump_jmemb_2026-06-14_15-47-26.hprof
+    JMemoryBuddy: no tracked references found in the dump; cannot compute a path to the GC root.
+
+TestJMemoryBuddy > testErrorMessages1() PASSED
+
+TestJMemoryBuddy > testErrorMessages2() STANDARD_OUT
+    Creating Heapdump at: /Users/floriankirmaier/projects/claude/JMemoryBuddy/build/heapdump_jmemb_2026-06-14_15-47-27.hprof
+
+    JMemoryBuddy — path to GC root for leak: Object @7e0175e48:
+      GC root [Java frame] Object
+
+
+TestJMemoryBuddy > testErrorMessages2() PASSED
+
+TestJMemoryBuddy > clearReferenceOnFinalization() STANDARD_OUT
+    Finalized!
+
+TestJMemoryBuddy > clearReferenceOnFinalization() PASSED
+
+TestJMemoryBuddy > negativeTest() STANDARD_OUT
+    Warning test seems to be unstable. time used: 100%
+    Creating Heapdump at: /Users/floriankirmaier/projects/claude/JMemoryBuddy/build/heapdump_jmemb_2026-06-14_15-47-28.hprof
+
+    JMemoryBuddy — path to GC root for leak: String @7e016bb00:
+      GC root [Java frame] String
+
+    The following references should be collected: [someText]
+
+TestJMemoryBuddy > negativeTest() PASSED
+
+TestJMemoryBuddy > simpleTestRepeated() PASSED
+
+TestJMemoryBuddyLive > testMarkKeepsGCBehaviour() PASSED
+
+Deprecated Gradle features were used in this build, making it incompatible with Gradle 9.0.
+
+You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.
+
+For more on this, please refer to https://docs.gradle.org/8.8/userguide/command_line_interface.html#sec:command_line_warnings in the Gradle documentation.
+
+BUILD SUCCESSFUL in 7s
+3 actionable tasks: 1 executed, 2 up-to-date

.tmp/jmb-compile.txt

@@ -0,0 +1,22 @@
+Downloading https://services.gradle.org/distributions/gradle-8.8-bin.zip
+.............10%.............20%.............30%.............40%.............50%.............60%..............70%.............80%.............90%.............100%
+WARNING: A restricted method in java.lang.System has been called
+WARNING: java.lang.System::load has been called by net.rubygrapefruit.platform.internal.NativeLibraryLoader in an unnamed module (file:/Users/floriankirmaier/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/native-platform-0.22-milestone-26.jar)
+WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
+WARNING: Restricted methods will be blocked in a future release unless native access is enabled
+
+Starting a Gradle Daemon (subsequent builds will be faster)
+
+FAILURE: Build failed with an exception.
+
+* What went wrong:
+BUG! exception in phase 'semantic analysis' in source unit '_BuildScript_' Unsupported class file major version 69
+> Unsupported class file major version 69
+
+* 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 26s

.tmp/jmb-multi.txt

@@ -0,0 +1,38 @@
+> Task :compileJava UP-TO-DATE
+> Task :processResources NO-SOURCE
+> Task :classes UP-TO-DATE
+
+> Task :compileTestJava
+/Users/floriankirmaier/projects/claude/JMemoryBuddy/src/test/java/one/jpro/jmemorybuddy/TestJMemoryBuddy.java:110: warning: [removal] finalize() in Object has been deprecated and marked for removal
+                protected void finalize() {
+                               ^
+/Users/floriankirmaier/projects/claude/JMemoryBuddy/src/test/java/one/jpro/jmemorybuddy/TestJMemoryBuddy.java:160: warning: [removal] finalize() in Object has been deprecated and marked for removal
+                    protected void finalize() {
+                                   ^
+2 warnings
+
+> Task :processTestResources NO-SOURCE
+> Task :testClasses
+
+> Task :test
+
+TestJMemoryBuddy > multiHopPath() STANDARD_OUT
+    Creating Heapdump at: /Users/floriankirmaier/projects/claude/JMemoryBuddy/build/heapdump_jmemb_2026-06-14_15-47-07.hprof
+
+    JMemoryBuddy — path to GC root for leak: Object @58a903060:
+      GC root [Java frame] TestJMemoryBuddy$Holder
+        ↓ TestJMemoryBuddy$Holder.field
+      Object   ← leaked
+
+    multiHopPath message: The following references should be collected: [java.lang.Object@3bd323e9]
+
+TestJMemoryBuddy > multiHopPath() PASSED
+
+Deprecated Gradle features were used in this build, making it incompatible with Gradle 9.0.
+
+You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.
+
+For more on this, please refer to https://docs.gradle.org/8.8/userguide/command_line_interface.html#sec:command_line_warnings in the Gradle documentation.
+
+BUILD SUCCESSFUL in 2s
+3 actionable tasks: 2 executed, 1 up-to-date