Try a 1 second delay to see if that solves the error.

This isn't a suitable thing to merge, but I simply don't understand
why this is failing on GH.

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/pdom/tests/PDOMProviderTests.java

@@ -196,6 +196,7 @@ public boolean providesFor(ICProject project) throws CoreException {
 				IBinding[] bindings = index.findBindings("A".toCharArray(), IndexFilter.ALL, npm());
 				assertEquals(1, bindings.length);
 				assertEquals(1, index.findDefinitions(bindings[0]).length);
+				Thread.sleep(1000);
 				bindings = index.findBindingsForPrefix("A".toCharArray(), false, new IndexFilter() {
 					@Override
 					public boolean acceptBinding(IBinding binding) {