help: configure: error: a working C++ compiler is required

["Mecislav Salar" <mecislavsalar%googlemail.com@localhost>]

i do not understand know why but i can not compile head code, it just
complains about `a working C++ compiler is required' ?

i use the command ./build.sh -O /usr/obj -T /usr/obj/tooldir.NetBSD-x86_64

dependall ===> groff
checking for gcc... cc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether cc accepts -g... yes
checking for cc option to accept ANSI C... none needed
checking whether we are using the GNU C++ compiler... yes
checking whether c++ accepts -g... yes
checking that C++ compiler can compile simple program... no
configure: error: a working C++ compiler is required

*** Failed target:  .configure_done
*** Failed command: (cd build && CC=cc CFLAGS=-O CPPFLAGS=\
-I/usr/obj/tools/compat\ -I/usr/obj/tools/compat/include\ \
-I/usr/src/tools/groff/../compat\ -DHAVE_NBTOOL_CONFIG_H=1\ \
-D_FILE_OFFSET_BITS=64 CXX=c++ CXXFLAGS=-O
INSTALL=/usr/obj/tooldir.NetBSD-x86_64/bin/x86_64--netbsd-install\ -c\
-p\ -r LDFLAGS= AR=ar RANLIB=ranlib
LEX=/usr/obj/tooldir.NetBSD-x86_64/bin/nblex
MAKE=/usr/obj/tooldir.NetBSD-x86_64/bin/nbmake
PATH="/usr/obj/tooldir.NetBSD-x86_64/bin:$PATH"
YACC=/usr/obj/tooldir.NetBSD-x86_64/bin/nbyacc /bin/sh
/usr/src/tools/groff/../../gnu/dist/groff/configure --without-x
--prefix=/usr/obj/tooldir.NetBSD-x86_64)
*** Error code 1

Stop.
nbmake: stopped in /usr/src/tools/groff

*** Failed target:  dependall
*** Failed command: cd /usr/src/tools/groff;
/usr/obj/tooldir.NetBSD-x86_64/bin/nbmake realall
*** Error code 1

Stop.
nbmake: stopped in /usr/src/tools/groff

*** Failed target:  dependall-groff
*** Failed command: _makedirtarget() { dir="$1"; shift; target="$1";
shift; case "${dir}" in /*) this="${dir}/"; real="${dir}" ;; .)
this=""; real="/usr/src/tools" ;; *) this="${dir}/";
real="/usr/src/tools/${dir}" ;; esac; show=${this:-.}; echo "${target}
===> ${show%/}${1:+ (with: $@)}"; cd "${real}" &&
/usr/obj/tooldir.NetBSD-x86_64/bin/nbmake _THISDIR_="${this}" "$@"
${target}; }; _makedirtarget groff dependall
*** Error code 1

Stop.
nbmake: stopped in /usr/src/tools

ERROR: Failed to make dependall tools
*** BUILD ABORTED ***

i deleted my /usr/src and cleared out /usr/obj then got a fresh
/usr/src but still complains about C++ compiler :(

my mk.conf

MAKEVERBOSE=0
MKATF=no
MKCVS=no
MKIPFILTER=no
MKGDB=no
MKHESIOD=no
MKHTML=no
MKISCSI=yes
MKLDAP=yes
MKMANZ=yes
MKMODULAR=yes
MKPCC=no
MKPCCCMDS=no
MKPIE=yes
MKPUFFS=yes
MKTEST=no
MKUPDATE=yes
MKX11=no
MKXORG=no
MKYP=no
USE_SSP=yes