Chris Jones writes:
> I've already updated by lex (and libl), and removed nslexer.c.  So
> what am I missing?
> 
> cc -O -DALL_STATE  -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith -Werror   -D_LIBC -DNLS -DYP -DHESIOD -DLIBC_SCCS -DSYSLIBC_SCCS -D_REENTRANT -I/usr/src/lib/libc/include -D__DBINTERFACE_PRIVATE -DRESOLVSORT -I. -DPOSIX_MISTAKE -DFLOATING_POINT -c nslexer.c
> cc1: warnings being treated as errors
> lex.yy.c:617: warning: no previous prototype for `yylex'
> /usr/src/lib/libc/net/nslexer.l: In function `yylex':
> /usr/src/lib/libc/net/nslexer.l:87: `_nsyylval' undeclared (first use this function)
> /usr/src/lib/libc/net/nslexer.l:87: (Each undeclared identifier is reported only once
> /usr/src/lib/libc/net/nslexer.l:87: for each function it appears in.)
> /usr/src/lib/libc/net/nslexer.l: At top level:
> /usr/src/lib/libc/net/nslexer.l:100: warning: function declaration isn't a prototype
> *** Error code 1
> 
> Stop.

is /usr/share/mk up to date? from cursory glances at your error
messages it appears that lex isn't being invoked with the appropriate
options to use `_nsyy' as the prefix (instead of `yy').