Ember 1.9 came out a few days ago, continuing along the path towards HTMLBars.

It took me longer than the expected 5 minutes to upgrade HungryBun due to a couple of small issues regarding support for Handlebars 2 in the build tools.

I had some problems with npm when trying to update the ember-template-compiler to the latest version.

npm ERR! peerinvalid The package handlebars does not satisfy its siblings' peerDependencies requirements!
npm ERR! peerinvalid Peer ember-template-compiler@1.9.0-alpha wants handlebars@~2
npm ERR! peerinvalid Peer grunt-ember-templates@0.5.0-alpha wants handlebars@~2.0.0

npm ERR! peerinvalid The package handlebars does not satisfy its siblings' peerDependencies requirements!
npm ERR! peerinvalid Peer ember-template-compiler@1.9.0-alpha wants handlebars@~2
npm ERR! peerinvalid Peer grunt-ember-templates@0.5.0-alpha wants handlebars@~2.0.0

The problem was being caused by fixed dependencies for Handlebars defined in my package.json

It used to look like this:

"devDependencies": {
  "handlebars": "~1.3.0",
  "ember-template-compiler": "~1.4.0-beta.1",
  "grunt-ember-templates": "~0.4.18",
}

You can safely remove all of those lines if you have them and then call

$ npm install grunt-ember-templates --save-dev

It will install the correct dependencies and result in package.json containing:

"devDependencies": {
  "grunt-ember-templates": "~0.5.0-alpha"
} 

Don't forget to recompile your templates!