locale related test fails on langtools mac 10.7 test host

tools/launcher/DiacriticalTest.java
fails on sc22ce403, a mac 10.7 machine.

java.nio.file.InvalidPathException: Malformed input or input contains unmappable chacraters: /Users/aurora/aurora/sandbox/results/workDir/tools/launcher/DiacriticTest/Class?.java
at sun.nio.fs.UnixPath.encode(UnixPath.java:147)
at sun.nio.fs.UnixPath.<init>(UnixPath.java:71)
at sun.nio.fs.UnixFileSystem.getPath(UnixFileSystem.java:281)
at java.io.File.toPath(File.java:2234)
at TestHelper.createFile(TestHelper.java:407)
at DiacriticTest.main(DiacriticTest.java:57)
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:491)
at com.sun.javatest.regtest.MainWrapper$MainThread.run(MainWrapper.java:94)
at java.lang.Thread.run(Thread.java:724)

It passes on a 10.9 machine, and on CORE-LIBS machines (include 10.7 machines).
Please investigate locale settings on test host.