Problems with raidframe under NetBSD-5.1/i386

[buhrow%lothlorien.nfbcal.org@localhost (Brian Buhrow)]

        Hello.  I have a box running NetBSD-5.1/i386 with kernel sources from
1/4/2011 which refuses to reconstruct to what looks like a perfectly good
disk.  The errormessages are:

Command:
root#raidctl -R /dev/sd10a raid2

Error messages from the kernel:
raid2: initiating in-place reconstruction on column 4
raid2: Recon write failed!
raid2: reconstruction failed.


So, I realize this isn't a lot to go on, so I've been trying to build a
kernel with some debugging in it.

Configured a kernel with:
options DEBUG
options RF_DEBUG_RECON

But the kernel won't build because the Dprintf statements that get turned
on in the rf_reconstruct.c file when the second option is enabled causes
gcc to emit warnings.  
        So, rather than fixing the warnings, and potentially breaking something
else, my question is, how can I turn off -werror in the build process for
just this kernel?  Looking in the generated Makefile didn't provide
enlightenment and I don't really want to disable this option for my entire
tree.  But, I imagine, this is an easy and often-wanted thing to do.
-thanks
-Brian