RELENG_6 Kernel doesn't build due to DEVFS

uname -a

FreeBSD bogushost 6.0-BETA4 FreeBSD 6.0-BETA4 #2: Mon Sep 12 23:01:45 
EDT 2005     root_at_bogushost:/usr/obj/usr/src/sys/ARL6AMD64  amd64

I haven't been able to build a GENERIC 6.0 kernel on amd64 for about a 
week now because of this error:

/usr/src/sys/fs/devfs/devfs_vnops.c:1148: warning: redundant 
redeclaration of 'devfs_ops_f'
/usr/src/sys/fs/devfs/devfs_vnops.c:70: warning: previous declaration of 
'devfs_ops_f' was here
/usr/src/sys/fs/devfs/devfs_vnops.c:1159: warning: redundant 
redeclaration of 'devfs_vnodeops'
/usr/src/sys/fs/devfs/devfs_vnops.c:68: warning: previous declaration of 
'devfs_vnodeops' was here
/usr/src/sys/fs/devfs/devfs_vnops.c:1181: warning: redundant 
redeclaration of 'd
evfs_specops'
/usr/src/sys/fs/devfs/devfs_vnops.c:69: warning: previous declaration of 
'devfs_specops' was here
*** Error code 1

For some reason, -Wall seems to be used when compiling this part of the 
kernel even though I didn't specify this to make.conf.  As far as 
devfs_vnops.c syntax goes, I've never used sparse declarations before, 
so I wouldn't know if that's improper syntax or not.  Since no one else 
seems to have complained about this, I'm wondering if I'm even following 
the right branch anymore.  For the record here's the version info for 
the offending source code:

  * $FreeBSD: src/sys/fs/devfs/devfs_vnops.c,v 1.114.2.5 2005/09/26 
14:36:52 phk Exp $