Ok, so this is a pretty minor issue but perhaps someone else might benefit from a quick solution. I was setting up a new openstack developer environment using devstack on a brand new Ubuntu 12.10 (ubuntu-server) and oops I got the following error when accessing horizon.
It seems it's a known bug, but it didn't list a fix. Well it's easy enough to address. A quick edit of files/apts/horizon to add nodejs-legacy, re-run ./stack.sh and normal operation is restored.