buildworld Failing in libc

Trying to build 5.2-CURRENT on a 5.2.1-RELEASE system. I've
gotten,

  ===> lib/libc
  cc -O -pipe -march=k6-2 -I/usr/src/lib/libc/include -I/usr/src/lib/libc/../../include -I/usr/src/lib/libc/i386 -D__DBINTERFACE_PRIVATE -I/usr/src/lib/libc/../../contrib/gdtoa -DINET6 -I/var/tmp/obj/usr/src/lib/libc -DPOSIX_MISTAKE -I/usr/src/lib/libc/locale -DBROKEN_DES -DPORTMAP -DDES_BUILTIN -I/usr/src/lib/libc/rpc -DYP -DHESIOD -Wsystem-headers -Werror -Wall -Wno-format-y2k -Wno-uninitialized -c nslexer.c
  /dev/stdout: In function `_nsyylex':
  /dev/stdout:711: warning: label `find_rule' defined but not used
  /usr/src/lib/libc/net/nslexer.l: At top level:
  /dev/stdout:1678: warning: `yy_flex_realloc' defined but not used
  *** Error code 1

  Stop in /usr/src/lib/libc.
  *** Error code 1

Two days in a row now. Looks like I can work around with
lowering WARNS in lib/libc/net, but anyone know why I might be
seeing this on this one system?
-- 
Crist J. Clark                     |     cjclark_at_alum.mit.edu
                                   |     cjclark_at_jhu.edu
http://people.freebsd.org/~cjc/    |     cjc_at_freebsd.org