rails.vim, Rextract error: "no such directory"

My first attempt at using Rextract to create a partial failed. I'm
trying to edit the file:

  views/layouts/application.html.erb

and create the partial:

  views/layouts/_application.html.erb

In visual line mode, I selected the lines in application.html.erb that I
want to be in the partial. Then I typed ':' which brought up:

:'<,'>

And I added:

:'<,'>Rextract stylesheets

But when I hit return, I was presented with an error message with a red
block
around it at the bottom of my macvim window that says:

  No such directory