Jasons-MacBook-Pro:practicesite fjord1321$ sudo yarn install
yarn install v1.7.0
warning package.json: No license field
warning No license field
[1/4] 🔍  Resolving packages...
 success Already up-to-date.
✨  Done in 0.34s.

Jasons-MacBook-Pro:practicesite fjord1321$ sudo yarn build
Password:
yarn run v1.7.0
warning ../../../../../package.json: No license field
error Command "build" not found.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation
about this command.

{
  "name": "gulp.sass",
  "version": "1.0.0",
  "description": "Gulp, SASS + Slow running tasks",
  "main": "gulpfile.js",
  "scripts": {
    "start": "gulp"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "browser-sync": "^2.2.0",
    "gulp": "^3.8.11",
    "gulp-sass": "^1.3.3",
    "through2": "^0.6.3"
  }
}