JUnit5SuiteExecutionTest fails with "Resource '/verification.tests.junit5' already exists." on Linux

[HannesWell]

At the moment, only on Linux the initialization of the test-class org.eclipse.pde.junit.runtime.tests.JUnit5SuiteExecutionTest persistently fails with the following error:

Resource '/verification.tests.junit5' already exists.
org.eclipse.core.internal.resources.ResourceException(/verification.tests.junit5)[374]: java.lang.Exception: Resource '/verification.tests.junit5' already exists.
	at org.eclipse.core.internal.resources.ResourceException.provideStackTrace(ResourceException.java:42)
	at org.eclipse.core.internal.resources.ResourceException.<init>(ResourceException.java:38)
	at org.eclipse.core.internal.resources.Resource.checkDoesNotExist(Resource.java:343)
	at org.eclipse.core.internal.resources.Resource.checkDoesNotExist(Resource.java:330)
	at org.eclipse.core.internal.resources.Project.assertCreateRequirements(Project.java:94)
	at org.eclipse.core.internal.resources.Project.create(Project.java:305)
	at org.eclipse.core.internal.resources.Project.create(Project.java:291)
	at org.eclipse.pde.ui.tests.util.ProjectUtils.importTestProject(ProjectUtils.java:180)
	at org.eclipse.pde.junit.runtime.tests.JUnitExecutionTest.setupProjects(JUnitExecutionTest.java:73)
	at org.eclipse.pde.junit.runtime.tests.JUnit5SuiteExecutionTest.setupProjects(JUnit5SuiteExecutionTest.java:40)
	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.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.RunBefores.invokeMethod(RunBefores.java:33)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:316)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:240)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:214)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:155)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.apache.maven.surefire.api.util.ReflectionUtils.invokeMethodWithArray2(ReflectionUtils.java:137)
	at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:148)
	at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:88)
	at org.eclipse.tycho.surefire.osgibooter.OsgiSurefireBooter.run(OsgiSurefireBooter.java:140)
	at org.eclipse.tycho.surefire.osgibooter.AbstractUITestApplication$1.run(AbstractUITestApplication.java:42)
	at org.eclipse.e4.ui.internal.workbench.swt.E4Testable.lambda$1(E4Testable.java:127)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:5040)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4520)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1151)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1042)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:152)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:639)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:546)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:152)
	at org.eclipse.tycho.surefire.osgibooter.UITestApplication.runApplication(UITestApplication.java:34)
	at org.eclipse.tycho.surefire.osgibooter.AbstractUITestApplication.run(AbstractUITestApplication.java:129)
	at org.eclipse.tycho.surefire.osgibooter.UITestApplication.start(UITestApplication.java:44)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:208)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:143)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:109)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:439)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:271)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:668)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:605)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1481)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1454)

This happens since #1349 but I would be surprised if this is related.

In general it is strange that this error even happens because the test-class also uses the ProjectUtils.DELETE_ALL_WORKSPACE_PROJECTS_BEFORE_AND_AFTER JUnit ClassRule to ensure the workspace is empty at the beginning and end of the test.
I can only explain it to me that something reproducibly creates the same resource in parallel, but only on Linux?
Could somebody on Linux try to debug this test? On Windows it passes as expected.