We see sporadic failures of this test in our CI. It occurs 4-5 times week and on all platforms we build (Linux, Windows, AIX, macOS). The first occurence in our CI was on the 8. October 2025.
We see this only in 25 at the moment.

----------System.out:(3/106)----------
sizeof(TestClassOld.class) == 457
TestClassXXX.foo() = java-lang-String
sizeof(TestClassNew.class) == 501
----------System.err:(14/914)----------
java.lang.NoClassDefFoundError: class names don't match
at java.instrument/sun.instrument.InstrumentationImpl.redefineClasses0(Native Method)
at java.instrument/sun.instrument.InstrumentationImpl.redefineClasses(InstrumentationImpl.java:247)
at RedefineClassHelper.redefineClass(RedefineClassHelper.java:61)
at ClassVersionAfterRedefine.main(ClassVersionAfterRedefine.java:97)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:565)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:1474)