libgee-0.8-dev
libgnome-menu-3-dev
libgtk-3-dev
libjson-glib-dev
libplank-dev
libsoup2.4-dev
libunity-dev
libwnck-3-dev
libzeitgeist-2.0-dev (optional)
pkg-config
valac
Just type from a command line:
meson build --prefix=/usr
cd build
ninja
sudo make install
./src/launchy