server start problem

[wanghaisheng]

I have successfully installed the torch and gfx.js on my ubuntu docker container.
when I want to start the server,
root@5054ff50ba22:/torch-tutorials# luajit -lgfx.start
luajit: /usr/local/share/lua/5.1/gfx/js.lua:14: attempt to concatenate a nil value
stack traceback:
/usr/local/share/lua/5.1/gfx/js.lua:14: in main chunk
[C]: in function 'require'
/usr/local/share/lua/5.1/gfx/start.lua:6: in main chunk
[C]: at 0x00463c70
[C]: at 0x004061d0