>So what's the bottom line? Even though FreeBSD 2.x has a sigsetjmp
>declaration in setjmp.h, is it broken in FreeBSD too?

I have no idea.

>What about the 4.4Lite version of BSD/OS?

BSD/OS 2.0 has a correct sigsetjmp.  I cannot speak for other
Lite-based systems....

>Not sure what is meant by `official'.

Um, all I meant was `what I could find that looked like X11R6' :-)

Anyway, flex has always (since the first public release, at least)
defined the symbol FLEX_SCANNER, so it is possible to auto-detect a
flex-built scanner.

Chris