On the CI build/test runs we are seeing testng reporting errors causing test runs to fail.
I find if I run using -othervm all tests pass but if I switch to -agentvm I get this stack trace from (some) testng tests:

----------System.err:(25/1549)----------
java.lang.ExceptionInInitializerError
at org.testng.reporters.Buffer.create(Buffer.java:5)
at org.testng.reporters.XMLStringBuffer.<init>(XMLStringBuffer.java:36)
at org.testng.reporters.XMLReporter.generateReport(XMLReporter.java:54)
at org.testng.TestNG.generateReports(TestNG.java:1115)
at org.testng.TestNG.run(TestNG.java:1074)
at com.sun.javatest.regtest.TestNGAction$TestNGRunner.main(TestNGAction.java:161)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:502)
at com.sun.javatest.regtest.MainAction$SameVMRunnable.run(MainAction.java:776)

Some tests/platforms(???) tack on this piece:
at java.lang.Thread.run(Thread.java:745)
Caused by: java.security.AccessControlException: access denied ("java.util.PropertyPermission" "fileStringBuffer" "read")
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:472)
at java.security.AccessController.checkPermission(AccessController.java:894)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:541)
at java.lang.SecurityManager.checkPropertyAccess(SecurityManager.java:1285)
at java.lang.System.getProperty(System.java:708)
at org.testng.reporters.FileStringBuffer.<clinit>(FileStringBuffer.java:30)
... 12 more

Sometime they fail with a different error but same stack trace:
----------System.err:(17/1001)----------
java.lang.NoClassDefFoundError: Could not initialize class org.testng.reporters.FileStringBuffer
...everything else is the same..

This test failure history has jtr links (all but 1 is this same failure):
http://java.se.oracle.com/mach5/view/9-dev-test-history/job/9-dev-tier2-linux-x64-failuresHistory/Failure_History/