langtools test test/tools/javac/T6405099.java
causes the following exception

----------Stack trace:(8/570)----------
java.lang.NullPointerException
at com.sun.javatest.regtest.RegressionScript.cleanDirectoryContents(Regr
essionScript.java:382)
at com.sun.javatest.regtest.RegressionScript.initScratchDirectory(Regres
sionScript.java:276)
at com.sun.javatest.regtest.RegressionScript.run(RegressionScript.java:8
8)
at com.sun.javatest.Script.run(Script.java:228)
at com.sun.javatest.DefaultTestRunner.runTest(DefaultTestRunner.java:167
)
at com.sun.javatest.DefaultTestRunner.access$100(DefaultTestRunner.java:
43)
at com.sun.javatest.DefaultTestRunner$1.run(DefaultTestRunner.java:66)
result: Not run. Test running...