As I played with include files while cleaning and as I introduced a new include file (tux_types.h), the makefile needs updating.
Normally I would do that straight away, but I saw that unix/Makefile was generated with MinGW, so I felt less confortable doig so.

Would the original developer of the makefile update it?
btw: personally I feel that as this is a unix makefile, it is a little bit odd to have it generated by MinGW; also I would like to see macros like $(SRCS) and a rule like

depend:
        makedepend -- $(CFLAGS) -- $(SRCS)

Yes I started the tuxdriver project with MINGWStudio both on linux and windows.
But this EDI is no more used to modifying these Makfiles now. I would to refactoring this in order to regularize it. Maybe AUTOMAKE is a better way to create it, but I don't have experience with it. If you have a good solution with a tutorial, I am taker

I'm not an expert either, but autoconf/automake seem widely used.

And of course I could not resist your offer, so here is are some tutorial links

http://www.amath.washington.edu/~lf/tutorials/autoconf/

http://vindaci.members.sonic.net/cbreak/projects/autotools/