scaffold generator creates layout file that links to non-existent css file

I run:

./script/generate scaffold Book title:string

It creates a layout file that includes:

<%= stylesheet_link_tag 'scaffold' %>

Which generates the following in the logs:

ActionController::RoutingError (No route matches "/stylesheets/scaffold.css"):

The expected behaviour is that if it generates a layout file linking to a css file, the css file should be there.

Ruby version 1.8.7 (universal-darwin10.0)
RubyGems version 1.3.5
Rack version 1.1
Rails version 3.0.pre
Edge Rails revision 87bcf1aa15f8edb4287e1916b65a2c523f765e86