only serial console -> build failure

gcc -Wp,-MD,drivers/char/.vt.o.d -D__KERNEL__ -Iinclude -Wall
-Wstrict-prototypes -Wno-trigraphs -O2 -fno-strict-aliasing -fno-common -pipe -mpreferred-stack-boundary=2 -march=pentium4 -Iinclude/asm-i386/mach-default -fomit-frame-pointer -nostdinc
-iwithprefix include -DKBUILD_BASENAME=vt -DKBUILD_MODNAME=vt -c -o
drivers/char/vt.o drivers/char/vt.c
drivers/char/vt.c: In function `vty_init':
drivers/char/vt.c:2518: `console_driver' undeclared (first use in this function)
drivers/char/vt.c:2518: (Each undeclared identifier is reported only once
drivers/char/vt.c:2518: for each function it appears in.) make[2]: *** [drivers/char/vt.o] Error 1
make[1]: *** [drivers/char] Error 2

[jgarzik@fokker2 atascsi-2.5]$ grep CONS .config
CONFIG_SCSI_CONSTANTS=y
# CONFIG_VT_CONSOLE is not set
CONFIG_HW_CONSOLE=y
CONFIG_SERIAL_8250_CONSOLE=y
CONFIG_SERIAL_CORE_CONSOLE=y
# CONFIG_VGA_CONSOLE is not set
# CONFIG_MDA_CONSOLE is not set
CONFIG_DUMMY_CONSOLE=y

Following up:

This only occurs when CONFIG_VT=y but not CONFIG_VT_CONSOLE=y.

Jeff