I keep removing functionality from my semi-GENERIC i386 kernel to try
to get the thing to build. Unfortunately, I've now hit the end of the
line. I presume the addition of all the -W stuff to kernel builds was
recent -- unfortunately, it appears to break lots of things :(

cc  -Werror -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -I. -I../../../../arch -I../../../.. -nostdinc -DI386_CPU -DI486_CPU -DI586_CPU -DMATH_EMULATE -DMACHINE_NONCONTIG -DTIMEZONE="0" -DDST="0" -DSWAPPAGER -DVNODEPAGER -DDEVPAGER -DRAMDISK_SERVER="0" -DRAMDISK_HOOKS -DMINIROOTSIZE="0x200" -DCOMPAT_10 -DCOMPAT_11 -DCOMPAT_12 -DEXEC_SCRIPT -DEXEC_AOUT -DLKM -DFFS -DMFS -DNFSCLIENT -DCD9660 -DMSDOSFS -DFDESC -DFIFO -DKERNFS -DINET -DMAXUSERS=32 -D_KERNEL  -Di386  -c ../../../../vm/vm_swap.c
cc1: warnings being treated as errors
../../../../vm/vm_swap.c: In function `swfree':
../../../../vm/vm_swap.c:465: warning: unused variable `sp'
../../../../vm/vm_swap.c:464: warning: unused variable `mp'
*** Error code 1

Stop.