Error: EACCES: permission denied, mkdir '/foldername'

While trying to deploy my meteor app using:

meteor build /foldername --mobile-settings settings.json --server=https://appname.herokuapp.com/

I get this error:

/Users/username/.meteor/packages/less/.2.7.9.1rcbr4q++os+web.browser+web.cordova/plugin.compileLessBatch.os/npm/node_modules/meteor/promise/node_modules/meteor-promise/promise_server.js:190
      throw error;
      ^

Error: EACCES: permission denied, mkdir '/foldername'
    at Error (native)
    at Object.fs.mkdirSync (fs.js:794:18)
    at Object.wrapper [as mkdir] (/tools/fs/files.js:1586:35)
    at Object.files.mkdir_p (/tools/fs/files.js:445:11)
    at buildCommand (/tools/cli/commands.js:977:11)
    at Command.func (/tools/cli/commands.js:831:12)
    at /tools/cli/main.js:1483:23

How do I fix it?

Solution

it's a permission issue. you have to be a super user before run your code. or else

sudo meteor build /foldername --mobile-settings settings.json --server=https://appname.herokuapp.com/

use the above code in your terminal.