[GRASSLIST:2232] can't find tk.h

[Richard Greenwood]

I am trying to build 5.0.3 on Cygwin, but configure is failing:

    checking for location of Tcl/Tk includes... /usr/local/include
    checking for tcl.h... yes
    checking for tk.h... no

But I have
    --with-tcltk-includes=/usr/local/include
 and  tk.h is in /usr/local/include !!!???

I think I am cross-eyed from looking at this for too long. What is it 
that I am missing?

Thanks,
Rich