The sparc64 build reaches over into the sparc build to do build
installboot. The Makefile for installboot doesn't support 64 bit builds,
even though the source code does. The following patch fixes this.

Using this patch, ./build.sh now runs to completeion for me.

Index: Makefile
===================================================================
RCS file: /vol/NetBSD/cvs-src/syssrc/sys/arch/sparc/stand/installboot/Makefile,v
retrieving revision 1.18
diff -u -r1.18 Makefile
--- Makefile	2001/10/31 22:13:03	1.18
+++ Makefile	2001/11/20 00:46:00
@@ -6,6 +6,9 @@
 PROG=	installboot
 SRCS=	installboot.c byteorder.c loadfile.c loadfile_aout.c \
 	loadfile_elf32.c
+.if ${MACHINE} == sparc64
+SRCS+=	loadfile_elf64.c
+.endif
 MKMAN=	no
 CFLAGS+=-g