Is cross-compiling netbsd from solaris supported?

I've tried to build a snapshot from a solaris-2.8 box and get the
following:


mcmahill@slashing 173 % ./build.sh -D /export/home0/mcmahill/netbsd-build
-R /export/home0/mcmahill/netbsd-snapshot -a sparc -m sparc
===> Bootstrapping nbmake
checking for gcc... cc
checking for C compiler default output... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for executable suffix... 
checking for object suffix... o
checking whether we are using the GNU C compiler... no
checking whether cc accepts -g... yes
checking how to run the C preprocessor... cc -E
checking for regex.h... yes
checking for regfree in -lregex... no
checking for library containing regfree... none required
checking for setenv... no
checking for strdup... yes
checking for strerror... yes
checking for strftime... yes
checking for vsnprintf... yes
configure: creating ./config.status
config.status: creating buildmake.sh
buildmake.sh: bad substitution

ERROR: build of nbmake failed
*** BUILD ABORTED ***



also I was hoping to try and build an alpha snapshot perhaps with:

env CC=cc CFLAGS="-xchip=ultra -dalign -xcode=abs32 -xarch=v9" ./build.sh
-D /export/home0/mcmahill/netbsd-build -R
/export/home0/mcmahill/netbsd-snapshot -a alpha -m alpha