How do I try the Octane preview on 3.14?

First, make sure you you are fully upgraded to Ember and Ember-CLI 3.14, including applying any blueprint changes (using ember-cli-update is recommended). Notably, the blueprint updates should have upgraded the following packages in your package.json, make sure you have them installed with npm/yarn:

• @ember/optional-features: ^1.0.0
• ember-cli-htmlbars: ^4.0.0

We are working on a tool that automate the following steps for you, if you are up for trying the work-in-progress tool, checkout its README. Otherwise, follow these steps manually.

Set the following optional features to the Octane values:

$ ember feature:disable jquery-integration
$ ember feature:enable template-only-glimmer-components
$ ember feature:disable application-template-wrapper

(See also My app uses jQuery... and What about default async observers?)

Add the following packages to your package.json:

• @glimmer/component: ^0.14.0-alpha.13 (Note: 0.13 does not work!)