Sass验证不起作用

Question

我尝试使用节点命令行检出sass stylesheet.scss文件 并输入： 学习ass验证stylesheet.scss 并且有一个错误：

Error: spawn C:\Users\Ksena\AppData\Roaming\npm\node_modules\learn-sass\node_modules\node-sass\bin\node-sass ENOENT
    at Process.ChildProcess._handle.onexit (internal/child_process.js:229:19)
    at onErrorNT (internal/child_process.js:406:16)
 at process._tickCallback (internal/process/next_tick.js:63:19)
Emitted 'error' event at:
    at Process.ChildProcess._handle.onexit (internal/child_process.js:235:12)
    at onErrorNT (internal/child_process.js:406:16)
    at process._tickCallback (internal/process/next_tick.js:63:19)

好的，我输入了以下命令：sudo npm install -g learn-sass，但是它拒绝工作。怎么了？