The following two tests failed in the JDK18 CI:

gc/stress/gcbasher/TestGCBasherWithZ.java#id0
gc/stress/gcbasher/TestGCBasherWithZ.java#id1

Here's a snippet from the TestGCBasherWithZ.java#id0 log file:

----------System.err:(18/1114)----------
java.lang.IllegalStateException
at gc.stress.gcbasher.ByteCursor.readUtf8(ByteCursor.java:110)
at gc.stress.gcbasher.Decompiler.decodeConstantPool(Decompiler.java:310)
at gc.stress.gcbasher.Decompiler.<init>(Decompiler.java:42)
at gc.stress.gcbasher.TestGCBasher.parseClassFiles(TestGCBasher.java:46)
at gc.stress.gcbasher.TestGCBasher.main(TestGCBasher.java:63)
at gc.stress.gcbasher.TestGCBasherWithZ.main(TestGCBasherWithZ.java:52)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:76)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:51)
at java.base/java.lang.reflect.Method.invoke(Method.java:569)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:833)

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

STATUS:Failed.`main' threw exception: java.lang.IllegalStateException
----------rerun:(39/7294)*----------

The second subtest, TestGCBasherWithZ.java#id1, failed
with the same output.