render :action raises ActionView::MissingTemplate
===

I have two controllers, `foo` and `bar`.  

`bar#dobar` has a corresponding `dobar.js.erb` file, which renders correctly when directly called with the accept header of 

    */*;q=0.5, text/javascript, application/javascript, application/ecmascript, application/x-ecmascript

`foo#dofoo` finishes with the command `render :action => '/bar/dobar'`.  This results in the following error message:


    ActionView::MissingTemplate (Missing template foo/bar/action, /application/bar/action with {:locale=>[:en], :formats=>[:js, "application/ecmascript", "application/x-ecmascript", :html, :text,
     :js, :css, :ics, :csv, :png, :jpeg, :gif, :bmp, :tiff, :mpeg, :xml, :rss, :atom, :yaml, :multipart_form, :url_encoded_form, :json, :pdf, :zip], :handlers=>[:erb, :builder, :coffee]}. 
    Searched in:
      * "/Developer/Workspace/MyProj/app/views"
      * "/Users/bdares/.rvm/gems/ruby-1.9.3-p194/gems/twitter-bootstrap-rails-2.1.0/app/views"
    ):
      app/controllers/foo_controller.rb:16:in `dofoo'

I've also tried `render :action => '/bar/dobar', :format => [:js]`.  What's wrong?