The test
langtools/jdk/jshell/CompletionSuggestionTest.java
routinely fails for me, when running tests on an Ubuntu Linux box.

Anecdotal evidence suggests I'm not the only one experiencing this.

It does sometime seem to pass when run standalone as a singleton test, so perhaps it is a resource issue of some sort.

When it fails, it shows the following:

test CompletionSuggestionTest.testImportStart(): failure
java.lang.AssertionError: Input: import c|, [com, completion_suggestion_test]: lists don't have the same size expected [1] but found [2]
at org.testng.Assert.fail(Assert.java:94)
at org.testng.Assert.failNotEquals(Assert.java:496)
at org.testng.Assert.assertEquals(Assert.java:125)
at org.testng.Assert.assertEquals(Assert.java:372)
at org.testng.Assert.assertEquals(Assert.java:539)
at KullaTesting.assertCompletion(KullaTesting.java:905)
at KullaTesting.assertCompletion(KullaTesting.java:900)
at CompletionSuggestionTest.testImportStart(CompletionSuggestionTest.java:299)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:563)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)