----------System.out:(10/632)----------
WB_CheckThreadObjOfTerminatingThread: target thread is protected
GCThread waiting ...
Target is terminating
WB_CheckThreadObjOfTerminatingThread: target thread is terminated
WB_CheckThreadObjOfTerminatingThread: GC has been initiated - checking threadObj:
WB_CheckThreadObjOfTerminatingThread: successful comparison on iteration 0
WB_CheckThreadObjOfTerminatingThread: successful comparison on iteration 1
WB_CheckThreadObjOfTerminatingThread: successful comparison on iteration 2
WB_CheckThreadObjOfTerminatingThread: successful comparison on iteration 3
WB_CheckThreadObjOfTerminatingThread: successful comparison on iteration 4
----------System.err:(4/198)----------

Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "GCThread"

Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "main"

It looks like the 7M heap is no longer big enough for ZGC.