sanity/WhiteBox.java fails with NPE

java.lang.NullPointerException
at java.util.Objects.requireNonNull(Objects.java:203)
at java.nio.file.Files.copy(Files.java:2983)
at ClassFileInstaller.main(ClassFileInstaller.java:52)
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:484)
at com.sun.javatest.regtest.MainWrapper$MainThread.run(MainWrapper.java:94)
at java.lang.Thread.run(Thread.java:745)