Parallel e2e test does not work for Windows (either activePerl or strawberryPerl). This is because IPC::Run module has limitation under Win32 (http://search.cpan.org/~toddr/IPC-Run-0.92/lib/IPC/Run.pm#Win32_LIMITATIONS). It will run into crash or deadlock. Fortunately cygwin perl does not use Win32 subsystem, and it does not have this issue. So we want to solve this by using cygwin perl.