npm run dev Error

i follow the [Guide](http://famous.org/get-started.html) , but when i run `npm run dev` i get error:

``` bash

engine-seed git:(master) npm run dev

> engine-seed@1.0.0 dev /Users/xieyiming/code/famous/engine-seed
> node ./bin/dev.js

serving /Users/xieyiming/code/famous/engine-seed/public on port 1618

module.js:340
throw err;
^
Error: Cannot find module 'glsl-tokenizer/string'
at Function.Module._resolveFilename (module.js:338:15)
at Function.Module._load (module.js:280:25)
at Module.require (module.js:364:17)
at require (module.js:380:17)
at Object. (/Users/xieyiming/code/famous/engine-seed/node_modules/famous/node_modules/glslify/node_modules/glslify-deps/index.js:1:78)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:364:17)

npm ERR! engine-seed@1.0.0 dev: `node ./bin/dev.js`
npm ERR! Exit status 8
npm ERR!
npm ERR! Failed at the engine-seed@1.0.0 dev script.
npm ERR! This is most likely a problem with the engine-seed package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! node ./bin/dev.js
npm ERR! You can get their info via:
npm ERR! npm owner ls engine-seed
npm ERR! There is likely additional logging output above.
npm ERR! System Darwin 14.1.1
npm ERR! command "/usr/local/bin/node" "/usr/local/bin/npm" "run" "dev"
npm ERR! cwd /Users/xieyiming/code/famous/engine-seed
npm ERR! node -v v0.10.24
npm ERR! npm -v 1.3.21
npm ERR! code ELIFECYCLE
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR! /Users/xieyiming/code/famous/engine-seed/npm-debug.log
npm ERR! not ok code 0

```