Ian,

Another problem, on the same Host/Target, "build.sh release":

--- cut ---
cat /usr/src-current/sys/arch/i386/i386/genassym.cf  |  sh /usr/src-current/
sys/kern/genassym.sh CC=/usr/src-current/obj/tooldir.NetBSD-1.6.1-i386/bin/
i386--netbsdelf-gcc /usr/src-current/obj/tooldir.NetBSD-1.6.1-i386/bin/
nbmkdep -f assym.dep      -ffreestanding  -O2 -Werror -Wall -Wno-main
-Wno-format-zero-length -Wpointer-arith -Wmissing-prototypes
-Wstrict-prototypes -Wno-sign-compare  -Di386 -I.  -I/usr/src-current/sys/
arch -I/usr/src-current/sys -nostdinc -DLKM -DMAXUSERS=32 -D_KERNEL
-D_KERNEL_OPT
cannot open assym.dep: no such file

*** Failed target:  .depend
*** Failed command: sed -e 's/.*\.o:.*\.c/assym.h:/' < assym.dep >> .depend
*** Error code 2

Stop.
nbmake: stopped in /usr/src-current/sys/arch/i386/compile/obj/GENERIC

*** Failed target:  kern-GENERIC
*** Failed command: cd /usr/src-current/sys/arch/i386/compile/obj/GENERIC && /
usr/src-current/obj/tooldir.NetBSD-1.6.1-i386/bin/nbmake depend && /usr/
src-current/obj/tooldir.NetBSD-1.6.1-i386/bin/nbmake
*** Error code 1

Stop.
nbmake: stopped in /usr/src-current/etc

*** Failed target:  release
*** Failed command: (cd /usr/src-current/etc && /usr/src-current/obj/
tooldir.NetBSD-1.6.1-i386/bin/nbmake INSTALL_DONE=1 release)
*** Error code 1

Stop.
nbmake: stopped in /usr/src-current

ERROR: Failed to make release
*** BUILD ABORTED ***
--- cut ---

Any ideas ?

I had a problem wich looked similar. Taking the current source tar files 
dated from 8 Nov and the build did go well.

Hope this helps
jakob