The following test failed in the JDK20 CI:

jdk/jshell/CommandCompletionTest.java

Here's a snippet from the log file:

config ReplToolTesting.setUp(): success
test CommandCompletionTest.testReload(): success
config ReplToolTesting.setUp(): success
test CommandCompletionTest.testReset(): success
config ReplToolTesting.setUp(): success
test CommandCompletionTest.testSave(): success
config ReplToolTesting.setUp(): success
test CommandCompletionTest.testSet(): failure
java.lang.AssertionError: Command: /set editor |, output: [/]: lists don't have the same size expected [2] but found [1]
at org.testng.Assert.fail(Assert.java:99)
at org.testng.Assert.failNotEquals(Assert.java:1037)
at org.testng.Assert.assertEqualsImpl(Assert.java:140)
at org.testng.Assert.assertEquals(Assert.java:122)
at org.testng.Assert.assertEquals(Assert.java:907)
at org.testng.Assert.assertEquals(Assert.java:1089)
at CommandCompletionTest.assertCompletion(CommandCompletionTest.java:89)
at CommandCompletionTest.assertCompletion(CommandCompletionTest.java:83)
at CommandCompletionTest.lambda$testSet$102(CommandCompletionTest.java:392)
at ReplToolTesting$PromptedCommandOutputStream.write(ReplToolTesting.java:824)
at java.base/java.io.PrintStream.implWrite(PrintStream.java:597)
at java.base/java.io.PrintStream.write(PrintStream.java:577)
at jdk.internal.le/jdk.internal.org.jline.terminal.impl.LineDisciplineTerminal.processOutputByte(LineDisciplineTerminal.java:253)
at jdk.internal.le/jdk.internal.org.jline.terminal.impl.LineDisciplineTerminal$FilteringOutputStream.write(LineDisciplineTerminal.java:294)
at java.base/sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:313)
at java.base/sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:409)
at java.base/sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:414)
at java.base/sun.nio.cs.StreamEncoder.lockedFlush(StreamEncoder.java:218)
at java.base/sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:205)
at java.base/java.io.OutputStreamWriter.flush(OutputStreamWriter.java:263)
at java.base/java.io.PrintWriter.implFlush(PrintWriter.java:417)
at java.base/java.io.PrintWriter.flush(PrintWriter.java:409)
at jdk.internal.le/jdk.internal.org.jline.terminal.impl.AbstractTerminal.flush(AbstractTerminal.java:177)
at jdk.internal.le/jdk.internal.org.jline.utils.Display.update(Display.java:340)
at jdk.internal.le/jdk.internal.org.jline.reader.impl.LineReaderImpl.redisplay(LineReaderImpl.java:3924)
at jdk.internal.le/jdk.internal.org.jline.reader.impl.LineReaderImpl.redisplay(LineReaderImpl.java:3784)
at jdk.internal.le/jdk.internal.org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:640)
at jdk.internal.le/jdk.internal.org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:468)
at jdk.jshell/jdk.internal.jshell.tool.ConsoleIOContext.readLine(ConsoleIOContext.java:223)
at jdk.jshell/jdk.internal.jshell.tool.JShellTool.getInput(JShellTool.java:1280)
at jdk.jshell/jdk.internal.jshell.tool.JShellTool.run(JShellTool.java:1214)
at jdk.jshell/jdk.internal.jshell.tool.JShellTool.start(JShellTool.java:1000)
at CommandCompletionTest.testRawRun(CommandCompletionTest.java:73)
at ReplToolTesting.testRaw(ReplToolTesting.java:296)
at ReplToolTesting.test(ReplToolTesting.java:249)
at ReplToolTesting.test(ReplToolTesting.java:233)
at CommandCompletionTest.testSet(CommandCompletionTest.java:386)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:132)
at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:599)
at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:174)
at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46)
at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:822)
at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:147)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.testng.TestRunner.privateRun(TestRunner.java:764)
at org.testng.TestRunner.run(TestRunner.java:585)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:384)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:378)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:337)
at org.testng.SuiteRunner.run(SuiteRunner.java:286)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1218)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1140)
at org.testng.TestNG.runSuites(TestNG.java:1069)
at org.testng.TestNG.run(TestNG.java:1037)
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:93)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:312)
at java.base/java.lang.Thread.run(Thread.java:1591)
config ReplToolTesting.setUp(): success
test CommandCompletionTest.testUserHome(): skip
org.testng.SkipException: No suitable file(s) found for this test in /opt/mach5
at CommandCompletionTest.testUserHome(CommandCompletionTest.java:363)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:132)
at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:599)
at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:174)
at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46)
at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:822)
at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:147)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at org.testng.TestRunner.privateRun(TestRunner.java:764)
at org.testng.TestRunner.run(TestRunner.java:585)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:384)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:378)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:337)
at org.testng.SuiteRunner.run(SuiteRunner.java:286)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1218)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1140)
at org.testng.TestNG.runSuites(TestNG.java:1069)
at org.testng.TestNG.run(TestNG.java:1037)
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:93)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:312)
at java.base/java.lang.Thread.run(Thread.java:1591)
config ReplToolTesting.setUp(): success
test CommandCompletionTest.testVarsMethodsTypes(): success

===============================================
jdk/jshell/CommandCompletionTest.java
Total tests run: 16, Passes: 14, Failures: 1, Skips: 1
===============================================

----------System.err:(10/528)----------
java.lang.Exception: failures: 1
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:95)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:312)
at java.base/java.lang.Thread.run(Thread.java:1591)

JavaTest Message: Test threw exception: java.lang.Exception
JavaTest Message: shutting down test

result: Failed. Execution failed: `main' threw exception: java.lang.Exception: failures: 1


This test also has a much older unresolved bug that describes
two other failure modes:

JDK-8148625 JShell tests: jdk/jshell/CommandCompletionTest.java test fails