I grabbed the "one true awk" source:

http://inferno.bell-labs.com/who/bwk/awk.sh

Compiles fine on SunOS 4.1.4, however, flex under NetBSD emits a
lex.yy.c that is a bunch of functions with undeclared variables.
On SunOS, lex emitted #define macros for the same stuff.

If anyone wants my lexyy.c and hacked makefile, I would be glad to
email it.  It's less than 50k total.

It takes the "one true lex" to build the "one true awk".

Or hack some variable declarations into the flex output...

And yes, I know, there is something slightly distasteful about using
SunOS to port to NetBSD. :-(
-- 
Rick Kelly	rmk@rmkhome.com	    rmk@tencats.rmkhome.com
                http://tencats.rmkhome.com