-> install build dependencies:
$ tce-load -wi compiletc ncursesw-dev automake

-> fix source code
$ cd ncdu-1.15.1
$ find . -type f | xargs sed -i 's|ncurses\.h|ncursesw/ncurses.h|'

-> per TC wiki, for maximum compatibility:
$ export CFLAGS="-mtune=generic -Os -pipe"
$ export CXXFLAGS="-mtune=generic -Os -pipe"
$ export LDFLAGS="-Wl,-O1"

-> finally:
$ ./configure --prefix=/usr/local
$ make
$ mkdir /opt/dest; sudo make DESTDIR=/opt/dest install