Problem building in Gerrit, Windows only.

Hi all,

a patch of mine:
<https://gerrit.libreoffice.org/#/c/30036/4>
always fails in Gerrit Windows build machine in test 
PythonTest_solenv_python:
<http://ci.libreoffice.org/job/lo_gerrit/1657/Config=windows_msc_dbgutil_32/console>

Unfortunately I'm not able to reproduce it on my Window 10 build machine 
(Win10 64bit, VS2013 64bit, LO 32bit) , where that same test doesn't fail.

I need help, because I have no idea what's going on.
May be make internal error, as stated in these build log lines:

"
make[3]: Entering directory 
'/home/tdf/lode/jenkins/workspace/lo_gerrit/Config/windows_msc_dbgutil_32/solenv/qa/python/selftest'
make[3]: *** internal error: invalid --jobserver-fds string 
'gmake_semaphore_5488'.  Stop.
make[3]: Leaving directory 
'/home/tdf/lode/jenkins/workspace/lo_gerrit/Config/windows_msc_dbgutil_32/solenv/qa/python/selftest'
"
can give some hint?

Following is the make version I use on Windows 10:
"
$ d:/lode/opt/bin/make --version
GNU Make 4.0
Built for Windows32
Copyright (C) 1988-2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
"
Help appreciated, thanks.

--
Kind Regards,
Giuseppe Castagno
Acca Esse http://www.acca-esse.eu
giuseppe.castagno at acca-esse.eu