Error with ionic setup sass


I have an error when starting sass for my app. Can you help please ?
My system is Ubununtu 14.04.

$ ionic setup sass
npmnpm WARN package.json snowboard@1.0.0 No README data
npm WARN package.json snowboard@1.0.0 No license field.
npm WARN prefer global ionic@1.6.4 should be installed with -g

Successful npm install
Updated /home/louisro/Documents/mobileApps/BoardLine/webapp_et_new_PGBuildversion/www/index.html <link href> references to sass compiled css

Ionic project ready to use Sass!
 * Customize the app using scss/
 * Run ionic serve to start a local dev server and watch/compile Sass to CSS

  throw new Error('`libsass` bindings not found. Try reinstalling `node-sass`?
Error: `libsass` bindings not found. Try reinstalling `node-sass`?
    at requireBinding (/home/louisro/Documents/mobileApps/BoardLine/webapp_et_new_PGBuildversion/node_modules/gulp-sass/node_modules/node-sass/sass.js:22:9)
    at Object.<anonymous> (/home/louisro/Documents/mobileApps/BoardLine/webapp_et_new_PGBuildversion/node_modules/gulp-sass/node_modules/node-sass/sass.js:25:15)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (/home/louisro/Documents/mobileApps/BoardLine/webapp_et_new_PGBuildversion/node_modules/gulp-sass/index.js:3:13)
    at Module._compile (module.js:460:26)

Error running gulp sass

Exception with  (CLI v1.6.4)

Your system information:

Cordova CLI: 5.3.1
Gulp version:  CLI version 3.9.0
Gulp local:   Local version 3.9.0
Ionic Version: 1.0.0-beta.13
Ionic CLI Version: 1.6.4
Ionic App Lib Version: 0.3.8
OS: Distributor ID:	Ubuntu Description:	Ubuntu 14.04.3 LTS 
Node Version: v0.12.7

Same here … running on OSX.
Any lead to solve this ?

I recently ran into the same thing.
I found this blog post helped explain and solve it.