Automatically render changed partials in webby

Question

I have a webby page and I'm have a layout that all my pages are rendered to. That layout uses a partial for navigation (in HAML):

= render(:partial => "navigation", :locals => {:some => "stuff"} )

The problem is that when I change the _navigation partial, neither webby nor webby autobuild recognize the change and they don't re-render the pages.

I've solved this by setting the dirty: true flag in the layout, but that makes all the pages re-render every time -- even when nothing changed.

I know that this is not that big a deal, but still: is there a way so that when you change partial, webby recognizes this and regenerates only the affected pages (as it does with everything else)?