compiling octave fails on building flex

[Marshall Floyd]

I have tried building mxe-octave in Ubuntu (in Virtual Box) with the 
intent of eventually cross compiling for Windows, but I'd be happy if I 
could get a linux version. I want many of the bug fixes and enhancements 
in the development version. I have used instructions from 
http://wiki.octave.org/Windows_Installer, http://wiki.octave.org/MXE, 
and http://wiki.octave.org/Octave_for_Debian_systems. Compilation fails 
while building flex. How can I fix the problem with building flex, or 
compile octave using the installed version of flex? I've tried a few 
things to avoid building flex, but I'm not sure exactly how to do that, 
e.g. ./configure --without-flex or make PKG_EXCLUDE='flex', and other 
variations. I can't find it now, but I've seen a partial answer on the 
help email list to a similar problem of setting some make option or 
looking at one of the .mk files for guidance suggesting that building 
make shouldn't have to be done. How can I do that?