The following test failed in the JDK18 CI with UT enabled:

gc/arguments/TestVerifyBeforeAndAfterGCFlags.java

Here's a snippet from the log file:

----------System.err:(1409/68356)----------
 stdout: [[0.101s][debug][gc,verify] GC(0) Threads
[0.102s][debug][gc,verify] GC(0) Heap
[0.102s][debug][gc,verify] GC(0) Roots

<snip>

1.344s][debug][gc,verify] GC(88) CodeCache Oops
[1.344s][debug][gc,verify] GC(88) ResolvedMethodTable Oops
[1.344s][debug][gc,verify] GC(88) String Deduplication
[1.344s][info ][gc,verify] GC(88) Verifying Before GC 13.054ms
[1.355s][debug][gc,verify] GC(88) Threads
[1.356s][debug][gc,verify] GC(88) Heap
[1.356s][debug][gc,verify] GC(88) Roots

<snip>

[1.428s][debug][gc,verify] GC(92) CodeCache Oops
[1.428s][debug][gc,verify] GC(92) ResolvedMethodTable Oops
[1.428s][debug][gc,verify] GC(92) String Deduplication
[1.428s][info ][gc,verify] GC(92) Verifying Before GC 10.792ms
[1.437s][debug][gc,verify] GC(92) Threads
[1.437s][debug][gc,verify] GC(92) Heap
[1.438s][debug][gc,verify] GC(92) Roots

<snip>

[1.449s][info ][gc,verify] GC(92) Verifying After GC 11.936ms
];
 stderr: []
 exitValue = 0

java.lang.RuntimeException: 'Verifying Before GC' found in stdout: 'Verifying Before GC'

at jdk.test.lib.process.OutputAnalyzer.shouldNotMatch(OutputAnalyzer.java:396)
at gc.arguments.TestVerifyBeforeAndAfterGCFlags.testVerifyFlags(TestVerifyBeforeAndAfterGCFlags.java:100)
at gc.arguments.TestVerifyBeforeAndAfterGCFlags.main(TestVerifyBeforeAndAfterGCFlags.java:69)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:312)
at java.base/java.lang.Thread.run(Thread.java:833)

JavaTest Message: Test threw exception: java.lang.RuntimeException