distro/collabora/cp-6.0* fails to build on my Ubuntu 16.04

Hey, on the libreoffice.org site it sais that this is the dev-
mailinglist, and on the bugtracker Buovjaga said, I should discuss it
here, so sorry if I'm posting into the wrong channel here,

I'm currently trying to rebuild my libreoffice online solution
I had a distro/collabora/cp-6.0 version working before, and built a
online version from branch distro/collabora/collabora-online-4 with
that, but when I rebuilt the online version, some errors happened that
looked like core issues, so I rebuilt core and it failed. i also tried
the distro/collabora/cp-6.0-29. Do i need another combination of
branches? I don't know what this cp means but it worked before ^^

here is the log, is anyone experiencing something like that as well? My
VServer is small, 2 cores and 4 Gigabytes of RAM and it doesn't even
have the Seccomp kernel module but i think this time it's not a RAM
issue :) I'm building on a single core to be sure i don't get RAM
issues or Admins thinking I'm doing mining :D

Heres the last bit of my build-log:

In file included from /usr/include/c++/5/memory:85:0,
                 from /usr/include/unicode/localpointer.h:45,
                 from /usr/include/unicode/uenum.h:23,
                 from /usr/include/unicode/ucnv.h:53,
                 from /usr/include/libxml2/libxml/encoding.h:31,
                 from /usr/include/libxml2/libxml/parser.h:810,
                 from /usr/include/libxml2/libxml/globals.h:18,
                 from /usr/include/libxml2/libxml/threads.h:35,
                 from /usr/include/libxml2/libxml/xmlmemory.h:218,
                 from /usr/include/libxml2/libxml/tree.h:1307,
                 from
/opt/libreoffice/libreoffice/workdir/UnpackedTarball/xmlsec/include/xml
sec/base64.h:18,
                 from
/opt/libreoffice/libreoffice/xmlsecurity/inc/xmlsec-wrapper.h:32,
                 from
/opt/libreoffice/libreoffice/xmlsecurity/source/xmlsec/biginteger.cxx:2
3:
/usr/include/c++/5/backward/auto_ptr.h:285:3: error: template
specialization with C linkage
   template<>
   ^
/usr/include/c++/5/backward/auto_ptr.h:293:3: error: template with C
linkage
   template<_Lock_policy _Lp>
   ^
/usr/include/c++/5/backward/auto_ptr.h:300:3: error: template with C
linkage
   template<typename _Tp, _Lock_policy _Lp>
   ^
/usr/include/c++/5/backward/auto_ptr.h:313:3: error: template with C
linkage
   template<typename _Tp>
   ^
/usr/include/c++/5/backward/auto_ptr.h:319:3: error: template with C
linkage
   template<typename _Tp, typename _Dp>
   ^
/opt/libreoffice/libreoffice/solenv/gbuild/LinkTarget.mk:291: recipe
for target
'/opt/libreoffice/libreoffice/workdir/CxxObject/xmlsecurity/source/xmls
ec/biginteger.o' failed
make[1]: ***
[/opt/libreoffice/libreoffice/workdir/CxxObject/xmlsecurity/source/xmls
ec/biginteger.o] Error 1