gulp-dev 报错不能找到sass模块

在github下了一个微信的H5动效模板 ,地址，按照说明操作，在gulp dev时报错，

pangangdeMacBook-Pro:wechat-h5-boilerplate pangang$ gulp -v
[10:01:02] CLI version 3.9.1
[10:01:02] Local version 3.9.1
pangangdeMacBook-Pro:wechat-h5-boilerplate pangang$ gulp dev
module.js:327
    throw err;
    ^

Error: Cannot find module 'gulp-sass'
    at Function.Module._resolveFilename (module.js:325:15)
    at Function.Module._load (module.js:276:25)
    at Module.require (module.js:353:17)
    at require (internal/module.js:12:17)
    at Object.<anonymous> (/Users/pangang/Desktop/wechat-h5-boilerplate/gulpfile.js:15:12)
    at Module._compile (module.js:409:26)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at Module.require (module.js:353:17)

gulpfile中sass代码如下

gulp.task('publish-css', function () {
    var cssVendors = vendors.stylesheets;

    return streamSeries(
        gulp.src(cssVendors),
        gulp.src('app/src/scss/main.scss')
            .pipe(plumber({
                errorHandler: errorAlert
            }))
            .pipe(sass({
                outputStyle: 'expanded'
            }))
            .pipe(autoprefixer())
    )
        .pipe(concat('bundle.css'))
        .pipe(gulp.dest('app/dist/stylesheets'))
        .pipe(browserSync.stream());
});

然后我想把sass下载到本地，也是报错。

$ npm install --save-dev sass
npm WARN excluding symbolic link index.js -> lib/sass.js
npm WARN excluding symbolic link lib/index.js -> sass.js
sass@0.5.0 node_modules/sass

---

看报错应该是需要npm install gulp-sass吧