Hi.

Running ./build.sh -O ../obj -T ../tools distribution 
on fresh source tree I get:

#    create  eqn/delim.d
CC=/usr/src/../tools/bin/i386--netbsdelf-gcc /usr/src/../tools/bin/nbmkdep
-f delim.d --   -DHAVE_CONFIG_H -I/usr/src/gnu/dist/groff/src/include
-I/usr/src/gnu/usr.bin/groff/src/include  -nostdinc++
-isystem-cxx  /usr/src/../obj/destdir.i386/usr/include/g++    -nostdinc
-isystem /usr/src/../obj/destdir.i386/usr/include   /usr/src/gnu/dist/groff/src/preproc/eqn/delim.cpp
#    create  eqn/eqn.d
CC=/usr/src/../tools/bin/i386--netbsdelf-gcc /usr/src/../tools/bin/nbmkdep
-f eqn.d --   -DHAVE_CONFIG_H -I/usr/src/gnu/dist/groff/src/include
-I/usr/src/gnu/usr.bin/groff/src/include  -nostdinc++
-isystem-cxx  /usr/src/../obj/destdir.i386/usr/include/g++    -nostdinc
-isystem /usr/src/../obj/destdir.i386/usr/include
eqn.cpp /usr/src/gnu/dist/groff/src/preproc/eqn/eqn.y:27:17: box.h: No
such file or directory nbmkdep: compile failed.

*** Failed target:  eqn.d
*** Failed command:
CC=/usr/src/../tools/bin/i386--netbsdelf-gcc /usr/src/../tools/bin/nbmkdep
-f eqn.d -- -DHAVE_CONFIG_H -I/usr/src/gnu/dist/groff/src/include
-I/usr/src/gnu/usr.bin/groff/src/include -nostdinc++
-isystem-cxx /usr/src/../obj/destdir.i386/usr/include/g++ -nostdinc
-isystem /usr/src/../obj/destdir.i386/usr/include eqn.cpp *** Error
code 1

Stop.
nbmake: stopped in /usr/src/gnu/usr.bin/groff/src/preproc/eqn

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

Stop.
nbmake: stopped in /usr/src/gnu/usr.bin/groff/src/preproc

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

Stop.
nbmake: stopped in /usr/src/gnu/usr.bin/groff/src

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

Stop.
nbmake: stopped in /usr/src/gnu/usr.bin/groff

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

Stop.
nbmake: stopped in /usr/src/gnu/usr.bin

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

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

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

Stop.
nbmake: stopped in /usr/src

*** Failed target:  do-build
*** Failed command: _makedirtarget() { dir="$1"; shift; target="$1";
shift; case "${dir}" in /*) this="${dir}/"; real="${dir}" ;; .)
this=""; real="/usr/src" ;; *) this="${dir}/";
real="/usr/src/${dir}" ;; esac; show=${this:-.}; echo "${target} ===>
${show%/}${1:+ (with: $@)}"; cd "${real}"
&& /usr/src/../tools/bin/nbmake _THISDIR_="${this}" "$@" ${target}; };
_makedirtarget . dependall BUILD_tools=no BUILD_lib=no *** Error code 1

Stop.
nbmake: stopped in /usr/src

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

Stop.
nbmake: stopped in /usr/src

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

Stop.
nbmake: stopped in /usr/src

ERROR: Failed to make distribution
*** BUILD ABORTED ***