It fails with:
#   compile  installboot/ffs.o
/build/tools/bin/powerpc--netbsd-gcc -Os -mmultiple -mstring  -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith -Wno-sign-compare -Wno-traditional -Wreturn-type -Wswitch -Wshadow -Wcast-qual -Wwrite-strings -Wextra -Wno-unused-parameter  -Werror   -DNO_FFS_SWAP -I/disk/wd1a/archive/cvs/src/usr.sbin/installboot -I.  -nostdinc -isystem /build/macppc.20061029/usr/include  -c    /disk/wd1a/archive/cvs/src/usr.sbin/installboot/ffs.c
cc1: warnings being treated as errors
/disk/wd1a/archive/cvs/src/usr.sbin/installboot/ffs.c: In function 'ffs_find_disk_blocks_ufs1':
/disk/wd1a/archive/cvs/src/usr.sbin/installboot/ffs.c:156: warning: empty body in an if-statement
/disk/wd1a/archive/cvs/src/usr.sbin/installboot/ffs.c:172: warning: empty body in an if-statement
/disk/wd1a/archive/cvs/src/usr.sbin/installboot/ffs.c: In function 'ffs_find_disk_blocks_ufs2':
/disk/wd1a/archive/cvs/src/usr.sbin/installboot/ffs.c:289: warning: empty body in an if-statement
/disk/wd1a/archive/cvs/src/usr.sbin/installboot/ffs.c:305: warning: empty body in an if-statement

 Thomas