The following test failed in the JDK20 CI:

gc/g1/mixedgc/TestOldGenCollectionUsage.java

Here's a snippet from the log file:

#section:main
----------messages:(7/1205)----------
command: main -Xbootclasspath/a:. -XX:+UseG1GC -XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -verbose:gc -XX:NewSize=2m -XX:MaxNewSize=2m -Xmx14m -Xms14m -XX:+AlwaysTenure -XX:InitiatingHeapOccupancyPercent=100 -XX:-G1UseAdaptiveIHOP -XX:G1MixedGCCountTarget=4 -XX:MaxGCPauseMillis=30000 -XX:G1HeapRegionSize=1m -XX:G1HeapWastePercent=0 -XX:G1MixedGCLiveThresholdPercent=100 gc.g1.mixedgc.TestOldGenCollectionUsage
reason: User specified action: run main/othervm -Xbootclasspath/a:. -XX:+UseG1GC -XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -verbose:gc -XX:NewSize=2m -XX:MaxNewSize=2m -Xmx14m -Xms14m -XX:+AlwaysTenure -XX:InitiatingHeapOccupancyPercent=100 -XX:-G1UseAdaptiveIHOP -XX:G1MixedGCCountTarget=4 -XX:MaxGCPauseMillis=30000 -XX:G1HeapRegionSize=1m -XX:G1HeapWastePercent=0 -XX:G1MixedGCLiveThresholdPercent=100 gc.g1.mixedgc.TestOldGenCollectionUsage
started: Fri Sep 16 01:26:15 UTC 2022
Mode: othervm [/othervm specified]
Additional options from @modules: --add-modules java.base,java.management --add-exports java.base/jdk.internal.misc=ALL-UNNAMED
finished: Fri Sep 16 01:26:15 UTC 2022
elapsed time (seconds): 0.218
----------configuration:(4/111)----------
Boot Layer
  add modules: java.base java.management
  add exports: java.base/jdk.internal.misc ALL-UNNAMED

----------System.out:(10/538)----------
[0.002s][info][gc] Using G1
Monitor G1 Old Gen pool with G1 Young Generation collector.
Found pool: G1 Old Gen
Found collector: G1 Young Generation
[0.187s][info][gc] GC(0) Pause Full (WhiteBox Initiated Full GC) 3M->1M(32M) 5.647ms
[0.193s][info][gc] GC(1) Pause Young (Normal) (G1 Evacuation Pause) 3M->3M(32M) 0.818ms
[0.194s][info][gc] GC(2) Pause Young (Normal) (WhiteBox Initiated Young GC) 3M->3M(32M) 0.192ms
G1 Old Gen: usage after GC = 1673496
G1 Young Generation: collection count = 2
G1 Young Generation: collection time = 0
----------System.err:(12/741)----------
java.lang.RuntimeException: Collector has not run
at gc.g1.mixedgc.TestOldGenCollectionUsage.run(TestOldGenCollectionUsage.java:122)
at gc.g1.mixedgc.TestOldGenCollectionUsage.main(TestOldGenCollectionUsage.java:62)
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.MainWrapper$MainThread.run(MainWrapper.java:125)
at java.base/java.lang.Thread.run(Thread.java:1589)

JavaTest Message: Test threw exception: java.lang.RuntimeException: Collector has not run