libpciaccess and MACHINE_GNU_PLATFORM

[Mark Davies <mark%ecs.vuw.ac.nz@localhost>]

Trying to build sysutils/libpciaccess on 6.1_STABLE/i386 currently fails 
for me with:

  CCLD     scanpci
../src/.libs/libpciaccess.so: undefined reference to `i386_set_mtrr'
../src/.libs/libpciaccess.so: undefined reference to `pcibus_conf_read'
../src/.libs/libpciaccess.so: undefined reference to `pcibus_conf_write'
*** [scanpci] Error code 1

because this bit of configure doesn't happen:

       *netbsd*)
                case $host in
                *i386*)
                        PCIACCESS_LIBS="$PCIACCESS_LIBS -li386 -lpci"

because $host is 'i486--netbsdelf'

because configure is invoked as

   ... /bin/sh './configure' --with-zlib --prefix=/usr/pkg --build=i486--
netbsdelf --host=i486--netbsdelf --mandir=/usr/pkg/man

which suggests MACHINE_GNU_PLATFORM is i486--netbsdelf

my question is why?  I thought the stuff in mk/bsd.prefs.mk was supposed 
to turn it into i386-unknown-netbsdelf6.1 like mk/gnu-config/config.guess 
does.

cheers
mark