Just call HotSpotDiagnostic.getDiagnosticOptions() and you get the exception below:

java.lang.NullPointerException
at sun.management.Flag.getVMOption(Flag.java:67)
at sun.management.HotSpotDiagnostic.getDiagnosticOptions(HotSpotDiagnostic.java:48)
at GetDiagnosticOptions.checkDiagnosticOptions(GetDiagnosticOptions.java:56)
at GetDiagnosticOptions.main(GetDiagnosticOptions.java:46)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:623)
at com.sun.javatest.regtest.MainWrapper$MainThread.run(MainWrapper.java:78)
at java.lang.Thread.run(Thread.java:674)

Works with 6u5 - throws NPE with 6u10 and OpenJDK 7.