This manifested itself as groff failing to be built which finally caused a 
fatal error during the build of the installation notes :-(.   That had me 
mightily confused until I came across the real error in the *middle* of 
the log files.  Any idea

1) Why the build didn't abort at the point of failure?
2) What needs fixing to make sunlabel build correctly on a non-netbsd host?

R.

./build.sh -a arm -B rearnsha-${build} -j 2 -m $target \
 -D /work/rearnsha/netbsd/build/install/$target \
 -O /work/rearnsha/netbsd/build/src/$target \
 -R /work/rearnsha/netbsd/build/dist/$target \
 -T /work/rearnsha/netbsd/build/tools/$target \
 -U 

$target is set to shark in the above.

--- sunlabel.lo ---
cc -O -DDISTRIB -I/work/rearnsha/netbsd/build/src/shark/tools/compat 
-I/work/rearnsha/netbsd/build/src/shark/tools/compat/include  
-I/work/rearnsha/netbsd/src/tools/sunlabel/../compat -DHAVE_CONFIG_H  
-D_FILE_OFFSET_BITS=64  -c -o sunlabel.lo.o /work/rearnsha/netbsd/src/tools
/sunlabel/../../usr.sbin/sunlabel/sunlabel.c
/work/rearnsha/netbsd/src/tools/sunlabel/../../usr.sbin/sunlabel/sunlabel.c
:54:27: sys/disklabel.h: No such file or directory
*** [sunlabel.lo] Error code 1
1 error