But exactly that causes the problem. And the beginning of the Makefile, there is this line:
LDFLAGS += -lncurses
This adds curses to ALL build targets, even if cross-compiling for Windows, were this won't work. So the main problem is, that the -lncurses flag shouldn't be set globally, but only if the target is a unix-ish system. 

I didn't build on windows either, but this is the cross-compiling section after all. So maybe we should test whether we are building for Windows first, and if not, just add the ncurses dependency.