Random failing org.eclipse.jface.text.tests.reconciler.FastAbstractReconcilerTest#testReplacingDocumentWhenClean()

[HeikoKlare]

org.eclipse.jface.text.tests.reconciler.FastAbstractReconcilerTest#testReplacingDocumentWhenClean() failed in a recent build (on MacOS): https://github.com/eclipse-platform/eclipse.platform.ui/pull/2704/checks?check_run_id=35665179984

reconciler never ran in 5 seconds
java.lang.AssertionError: reconciler never ran in 5 seconds
	at org.junit.Assert.fail(Assert.java:89)
	at org.eclipse.jface.text.tests.reconciler.AbstractReconcilerTest$Barrier.await(AbstractReconcilerTest.java:103)
	at org.eclipse.jface.text.tests.reconciler.AbstractReconcilerTest.testReplacingDocumentWhenClean(AbstractReconcilerTest.java:337)

[vogella]

Also on Linux #3453

1 out of 3 runs failed: testReplacingDocumentWhenClean (JFaceTextTestSuite FastAbstractReconcilerTest)

expected:<[reconcilerReset]> but was:<[process]>
org.junit.ComparisonFailure: expected:<[reconcilerReset]> but was:<[process]>
at org.eclipse.jface.text.tests.reconciler.AbstractReconcilerTest.testReplacingDocumentWhenClean(AbstractReconcilerTest.java:336)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)