It looks like both mac68k and macppc are failing to build for the  
same reason:

/usr/src/dist/pdisk/dump.c:740: warning: passing arg 2 of `error'  
discards qualifiers from pointer target type
/usr/src/dist/pdisk/dump.c:745: warning: passing arg 2 of `error'  
discards qualifiers from pointer target type
/usr/src/dist/pdisk/dump.c:754: warning: passing arg 2 of `error'  
discards qualifiers from pointer target type
/usr/src/dist/pdisk/dump.c:762: warning: passing arg 2 of `error'  
discards qualifiers from pointer target type

*** Failed target:  dump.o
*** Failed command: /home/build/obj/macppc/tooldir.NetBSD-2.0H-i386/ 
bin/powerpc--netbsd-gcc -O2 -Wall -Wstrict-prototypes -Wmissing- 
prototypes -Wpointer-arith -Wno-sign-compare -Wno-traditional - 
Wreturn-type -Wswitch -Wshadow -Wcast-qual -Wwrite-strings -Werror -I/ 
usr/src/dist/pdisk -D__unix__ -nostdinc -isystem /home/build/dst/ 
macppc/usr/include -c /usr/src/dist/pdisk/dump.c
*** Error code 1

Stop.
nbmake: stopped in /usr/src/sbin/pdisk