I am doing a program, I meet some question when I use the npm script with Mac system;  

 I have already install the node-sass globally, the package.json file is as follows: [package.json](http://i.stack.imgur.com/YI4gW.png)  

it is not work when I run "npm run build:css",while the error the system tell me is as the follow picture:
[the err discription](http://i.stack.imgur.com/l8qsg.jpg)
**but** I can run the commend `node-sass ./src/scss/pages/index.scss ./static/css/index.css` successfully in the terminal and if I add another line like `"create":"touch sun.js"` to package.json, it works well when I run `npm run create`; 

I am confused, I will be grateful if someone can give some suggestion.