Exceptions at the end of worker executions

I’m seeing some strange executions being thrown from workers that run as PROCESS. I have mostly noticed this under Windows, but on the odd occasion under MacOS too. JDK8 or 10 makes no difference.
So far it has always been when a test is run through TestKit and that test then kicks off a jib in a worker.

The test always passes fine, but an exception such as below is thrown at the end of the test run, So far the only common factor is PROCESS. If I run the same tests using CLASSPATH for the worker or even just run it via javaexec no such problem occurs,

I am perplexed to say the least.

org.gradle.process.internal.ExecException: Process 'Gradle Worker Daemon 1' finished with non-zero exit value 1
        at org.gradle.process.internal.DefaultExecHandle$ExecResultImpl.assertNormalExitValue(DefaultExecHandle.java:389)
        at org.gradle.process.internal.worker.DefaultWorkerProcess.waitForStop(DefaultWorkerProcess.java:210)
        at org.gradle.process.internal.worker.DefaultWorkerProcessBuilder$MemoryRequestingWorkerProcess.waitForStop(DefaultWorkerProcessBuilder.java:228)
        at org.gradle.process.internal.worker.DefaultMultiRequestWorkerProcessBuilder$1.invoke(DefaultMultiRequestWorkerProcessBuilder.java:144)
        at com.sun.proxy.$Proxy129.stop(Unknown Source)
        at org.gradle.workers.internal.WorkerDaemonClient.stop(WorkerDaemonClient.java:61)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.workers.internal.WorkerDaemonClientsManager.stopWorkers(WorkerDaemonClientsManager.java:139)
        at org.gradle.workers.internal.WorkerDaemonClientsManager.stop(WorkerDaemonClientsManager.java:108)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$ManagedObjectServiceProvider.stop(DefaultServiceRegistry.java:597)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$ManagedObjectServiceProvider.stop(DefaultServiceRegistry.java:597)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$ManagedObjectServiceProvider.stop(DefaultServiceRegistry.java:597)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$OwnServices.stop(DefaultServiceRegistry.java:489)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$CompositeServiceProvider.stop(DefaultServiceRegistry.java:1002)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry.close(DefaultServiceRegistry.java:257)
        at org.gradle.internal.concurrent.CompositeStoppable$2.stop(CompositeStoppable.java:88)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.scopes.DefaultGradleUserHomeScopeServiceRegistry.close(DefaultGradleUserHomeScopeServiceRegistry.java:62)
        at org.gradle.internal.concurrent.CompositeStoppable$2.stop(CompositeStoppable.java:88)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$ManagedObjectServiceProvider.stop(DefaultServiceRegistry.java:597)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$OwnServices.stop(DefaultServiceRegistry.java:489)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$CompositeServiceProvider.stop(DefaultServiceRegistry.java:1002)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry.close(DefaultServiceRegistry.java:257)
        at org.gradle.internal.concurrent.CompositeStoppable$2.stop(CompositeStoppable.java:88)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.tooling.internal.provider.DefaultConnection.shutdown(DefaultConnection.java:154)
        at org.gradle.tooling.internal.consumer.connection.ShutdownAwareConsumerConnection.stop(ShutdownAwareConsumerConnection.java:35)
        at org.gradle.tooling.internal.consumer.connection.ParameterValidatingConsumerConnection.stop(ParameterValidatingConsumerConnection.java:35)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.tooling.internal.consumer.loader.CachingToolingImplementationLoader.close(CachingToolingImplementationLoader.java:53)
        at org.gradle.internal.concurrent.CompositeStoppable$2.stop(CompositeStoppable.java:88)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.tooling.internal.consumer.loader.SynchronizedToolingImplementationLoader.close(SynchronizedToolingImplementationLoader.java:63)
        at org.gradle.internal.concurrent.CompositeStoppable$2.stop(CompositeStoppable.java:88)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$ManagedObjectServiceProvider.stop(DefaultServiceRegistry.java:597)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry$OwnServices.stop(DefaultServiceRegistry.java:489)
        at org.gradle.internal.concurrent.CompositeStoppable.stop(CompositeStoppable.java:103)
        at org.gradle.internal.service.DefaultServiceRegistry.close(DefaultServiceRegistry.java:257)
        at org.gradle.tooling.internal.consumer.ConnectorServices.close(ConnectorServices.java:50)
        at org.gradle.tooling.internal.consumer.DefaultGradleConnector.close(DefaultGradleConnector.java:57)
        at org.gradle.testkit.runner.internal.ToolingApiGradleExecutor$1.run(ToolingApiGradleExecutor.java:75)
        at java.lang.Thread.run(Thread.java:748)