[Buildroot] nano package fail to build; cannot include curses.h

[William Tambe]

Nano package fail to build with the following error:

nano.h:89:10: fatal error: curses.h: No such file or directory

curses.h library can be found in the following path:
./target/usr/include/curses.h
./target/usr/include/ncurses.h
./host/iron-buildroot-linux-gnu/sysroot/usr/include/curses.h
./host/iron-buildroot-linux-gnu/sysroot/usr/include/ncurses.h
./host/include/ncurses/curses.h
./host/include/ncurses/ncurses.h

Any idea why the nano package fail to build despite the headers being
available ?