Situation:  VS3100/M76, 24 megs.  Attempting my first "make build".
Sup'ed sources a couple of days ago, started build.  Failed a 
couple of times due to "unable to allocate memory".  Searched 
a bit, found stuff on archives about unlimit; build got there.
Went to bed.  This morning, build had failed when compiling
dd, as follows:

cc -O2 -pipe  -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith -Werror   -c dd.c
cc1: warnings being treated as errors
dd.c: In function `setup':
dd.c:159: warning: null format string
dd.c:164: warning: null format string
*** Error code 1

Stop.
<further lines elided>

The lines referenced are both " err(1, NULL);"  Warnings treated as errors?
Why?  As I said, this is my first NETBSD build, so I'm not
sure I did everything right,  but this looks slightly broken?
Anybody got a clue they can send my way?