./waf build error

Hi. After succed in running all install and , ./waf distclean , ./waf configure the ./waf build fail with this error :

Build failed
 -> task failed (exit status 1):
 {task 146715980: valac main.vala,webviews.vala,javascriptcore-tools.vala,js-api.vala,service.vala,application.vala,player.vala,mpris.vala,helper.vala,dock_manager.vala,media_keys.vala,ubuntu_sound_menu.vala,trayicon.vala,unity_launcher.vala,storage.vala,windows.vala,actions.vala,settings.vala,preferences.vala,keybindings.vala,logger.vala,config.vala,path.vala,widgets.vala,app.vala,system.vala,connection.vala,tools.vala -> main.c,webviews.c,javascriptcore-tools.c,js-api.c,service.c,application.c,player.c,mpris.c,helper.c,dock_manager.c,media_keys.c,ubuntu_sound_menu.c,trayicon.c,unity_launcher.c,storage.c,windows.c,actions.c,settings.c,preferences.c,keybindings.c,logger.c,config.c,path.c,widgets.c,app.c,system.c,connection.c,tools.c}