Form_for not working with Markaby

I’m playing around with Markaby and I decided to write a little blog
app.
I’m running into issues with forms however. If I use form_for the output
of
the form gets swallowed. For example:

form_for :article, @article do |f|
f.text_field :title
f.check_box :published
f.text_area :description
f.text_field :pub_date
f.text_area :content
end

gets rendered as an empty form tag. The above code of course works fine
in
an rhtml file (with appropriate erb tags). Oddly form_tag works fine in
Markaby:

form_tag :action => ‘create’
text_field ‘article’, ‘title’
check_box ‘article’, ‘published’
text_area ‘article’, ‘description’
text_field ‘article’, ‘pub_date’
text_area ‘article’, ‘content’

end_form_tag

Renders the form just fine.

Anyone have thoughts on why this would be? I really like Markaby, and I
also
prefer the form_for syntax, so ideally I would like to use both. Any
help
would be appreciated.