I tried installing Ada using the wip package.
I have the same problem.

Here is the output of uname -a

NetBSD deneb.stars.net 2.0G NetBSD 2.0G (GENERIC) #0: Fri Jul 16 20:18:25 UTC 
20
04  
autobuild@b1.urc.uninett.no:/usr/users/autobuild/autobuild/HEAD/i386/OBJ/usr
/users/autobuild/autobuild/HEAD/src/sys/arch/i386/compile/GENERIC i386

In the directory /usr/pkgsrc/wip/gcc-3.4-ada I edited the Makefile
to uncomment the following line:
USE_GCC34       =# Define to use gcc34
I didn't touch  /usr/pkgsrc/wip/gcc-3.4/Makefile.

make successfully builds gcc-3.4 and, after returning to the build
of gcc-3.4-ada displays the following:

... (output removed) ...
Bootstrapping the compiler
gmake[1]: Entering directory `/usr/pkgsrc/wip/gcc-3.4-ada/work/obj/gcc'
... .(output removed) ...
echo timestamp > stage3_build
echo stage3_build > stage_last
gmake[3]: Leaving directory `/usr/pkgsrc/wip/gcc-3.4-ada/work/obj/gcc'
gmake[2]: Leaving directory `/usr/pkgsrc/wip/gcc-3.4-ada/work/obj/gcc'
gmake[1]: Leaving directory `/usr/pkgsrc/wip/gcc-3.4-ada/work/obj'
(cd /usr/pkgsrc/wip/gcc-3.4-ada/work/obj/gcc && /usr/bin/env USETOOLS=no 
PTHREAD
BASE=/usr MAKECONF=/dev/null USETOOLS="no" OBJECT_FMT="ELF" LDFLAGS=" 
-L/usr/pkg
/gcc34/lib -L/usr/pkg/gcc34/lib/gcc/i386--netbsdelf2.0/3.4.1/ -L/usr/lib 
-Wl,-R/
usr/lib -Wl,-R/usr/pkg/lib" RPATH_FLAG="-R" 
WHOLE_ARCHIVE_FLAG="-Wl,--whole-arch
ive" NO_WHOLE_ARCHIVE_FLAG="-Wl,--no-whole-archive" LINK_ALL_LIBGCC_HACK="" 
PATH
=/usr/pkgsrc/wip/gcc-3.4-ada/work/.buildlink/bin:/usr/pkgsrc/wip/gcc-3.4-ada/wor
k/.tools/bin:/usr/pkgsrc/wip/gcc-3.4-ada/work/.gcc/bin:/sbin:/usr/sbin:/bin:/usr
/bin:/usr/pkg/sbin:/usr/pkg/bin:/usr/X11R6/bin:/usr/local/sbin:/usr/local/bin:/u
sr/pkg/bin:/usr/X11R6/bin PREFIX=/usr/pkg LOCALBASE=/usr/pkg 
X11BASE=/usr/X11R6
CFLAGS="-O2 -I/usr/pkgsrc/wip/gcc-3.4-ada/work/.buildlink/include 
-I/usr/pkg/gcc
34/include -I/usr/pkg/gcc34/lib/gcc/i386--netbsdelf2.0/3.4.1/include 
-I/usr/incl
ude" CPPFLAGS=" -I/usr/pkgsrc/wip/gcc-3.4-ada/work/.buildlink/include  
-I/usr/pk
g/gcc34/include -I/usr/pkg/gcc34/lib/gcc/i386--netbsdelf2.0/3.4.1/include 
-I/usr
/include" FFLAGS="-O" X11PREFIX=/usr/pkg CC="gcc" CXX="g++" CPP="cpp" 
PTHREAD_CF
LAGS="-pthread" PTHREAD_LDFLAGS=" -lpthread" BSD_INSTALL_PROGRAM="install -c 
-s
-o root -g wheel -m 555"                 BSD_INSTALL_SCRIPT="install -c -o 
root
-g wheel -m 555"                         BSD_INSTALL_LIB="install -c -o root 
-g
wheel -m 555"                    BSD_INSTALL_DATA="install -c -o root -g wheel 
-
m 444"                   BSD_INSTALL_MAN="install -c -o root -g wheel -m 444"
                 BSD_INSTALL="install"                           
BSD_INSTALL_PRO
GRAM_DIR="install -d -o root -g wheel -m 755"    
BSD_INSTALL_SCRIPT_DIR="install
 -d -o root -g wheel -m 755"             BSD_INSTALL_LIB_DIR="install -d -o 
root
 -g wheel -m 755"                BSD_INSTALL_DATA_DIR="install -d -o root -g 
whe
el -m 755"               BSD_INSTALL_MAN_DIR="install -d -o root -g wheel -m 
755
"                BSD_INSTALL_GAME="install -c -s -o root -g wheel -m 555" 
PKG_SY
SCONFDIR="/usr/pkg/etc" 
INSTALL_INFO="/usr/pkgsrc/wip/gcc-3.4-ada/work/.tools/bi
n/install-info" 
MAKEINFO="/usr/pkgsrc/wip/gcc-3.4-ada/work/.tools/bin/makeinfo"
BUILDLINK_CACHE_ALL=yes  VIEWBASE=/usr/pkg /usr/pkg/bin/gmake 
gnatlib_and_tools)
gmake: *** No rule to make target `gnatlib_and_tools'.  Stop.
*** Error code 2

Stop.
make: stopped in /usr/pkgsrc/wip/gcc-3.4-ada
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/wip/gcc-3.4-ada