I tried with and without CURSES_DEFAULT=ncurses, same result.
In case someone is interested, I found out that if one has ncurses
installed, the lldb cmake build process finds it, despite the system
curses library being explicitly included in the package Makefile; even
if one forces CMAKE_ARGS+= -DLLDB_DISABLE_CURSES:BOOL=TRUE in the
Makefile, ncurses is still discovered and the build fails.
I was able to build it by hand-editing a couple of link.txt files in
the build directory to include libncurses and libterminfo.
BTW similar happens with shells/fish if CURSES_DEFAULT is ncurses.