Server start failed: undefined function

[Gab-Metzger]

Hello,

I'm trying to start your demo app but when I run ember serve I have an error:

undefined is not a function
TypeError: undefined is not a function
    at rimraf (/Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/broccoli-caching-writer/node_modules/rimraf/rimraf.js:59:36)
    at lib$rsvp$node$$tryApply (/Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/broccoli-caching-writer/node_modules/rsvp/dist/rsvp.js:1467:11)
    at lib$rsvp$node$$handleValueInput (/Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/broccoli-caching-writer/node_modules/rsvp/dist/rsvp.js:1567:20)
    at fn (/Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/broccoli-caching-writer/node_modules/rsvp/dist/rsvp.js:1555:18)
    at /Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/broccoli-caching-writer/index.js:100:14
    at lib$rsvp$$internal$$tryCatch (/Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/promise-map-series/node_modules/rsvp/dist/rsvp.js:489:16)
    at lib$rsvp$$internal$$invokeCallback (/Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/promise-map-series/node_modules/rsvp/dist/rsvp.js:501:17)
    at lib$rsvp$$internal$$publish (/Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/promise-map-series/node_modules/rsvp/dist/rsvp.js:472:11)
    at lib$rsvp$asap$$flush (/Users/gabrielmetzger/Documents/Workspace/EmberJS/treasure-hunt/node_modules/ember-cli/node_modules/promise-map-series/node_modules/rsvp/dist/rsvp.js:1290:9)
    at process._tickCallback (node.js:355:11)

My process was:

git clone
npm install && bower install
ember serve

Is this a known issue ? Thanks, Gabriel METZGER