当我编译时gulp,我收到如下错误.我该如何解决？
module.js:339
throw err;
^
Error: Cannot find module 'gulp-sass'
at Function.Module._resolveFilename (module.js:337:15)
at Function.Module._load (module.js:287:25)
at Module.require (module.js:366:17)
at require (module.js:385:17)
at Object.<anonymous> (/Applications/XAMPP/xamppfiles/htdocs/flyscoot.com/gulpfile.js:2:12)
at Module._compile (module.js:435:26)
at Object.Module._extensions..js (module.js:442:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:311:12)
at Module.require (module.js:366:17)