Is there something corrupt in my environment to cause this failure
trying to build -current cvs'ed yesterday?

cc -O2 -DALL_STATE -DUSG_COMPAT  -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith -Wno-uninitialized -Wreturn-type -Wpointer-arith -Wswitch -Wshadow -Werror   -D_LIBC -DNLS -DYP -DHESIOD -DLIBC_SCCS -DSYSLIBC_SCCS  -D_REENTRANT -I/usr/src/lib/libc/include -DINET6 -D__DBINTERFACE_PRIVATE -DWITH_RUNE -DRUNEMOD_MAJOR=3  -D_PATH_LOCALEMODULE=\"/usr/lib/runemodule\" -DRESOLVSORT -I. -DPOSIX_MISTAKE -DPORTMAP -DFLOATING_POINT    -c /usr/src/lib/libc/net/res_mkquery.c
cc1: warnings being treated as errors
/usr/src/lib/libc/net/res_mkquery.c: In function `__res_opt':
/usr/src/lib/libc/net/res_mkquery.c:242: warning: declaration of `__x' shadows previous local
*** Error code 1

Stop.
make: stopped in /usr/src/lib/libc