Ember build blocked by corporate proxy

I am forced to use an older version of ember-cli (0.1.2) and node (0.10.33) and npm (1.4.28) and work behind a corporate proxy.

I have set my proxy within npm and running npm install completes successfully.

However, when I run ember build, my vendor.js contains HTML pages returned by my corporate proxy, which say I haven't provided my credentials. As a result when I try to ember s the browser can't parse the vendor.js file and blows up.

Does anyone know how to tell ember-cli to use my working npm proxy settings? I've tried approximately 12,034 different formats of strings in npm all of which work, but none of which allow ember-cli to build properly.