render :text => proc and CSV::Writer

Hi all.

In my Rails 2.1 code (I am skipping 2.2...) used to do something like
this from a reports controller:

    render_proc = proc do |response, output|
      CSV::Writer.generate(output) do |csv|
        csv << [ 'Login', 'Name', 'Email' ]
        User.find(:all).each do |user|
          csv << [ user.login, user.name, user.email ]
        end
      end
    end

    render :layout => false, :text => render_proc

This no longer works because CSV:Writer wants to call <<() and it is
not defined.

Was this removal intentional?

As a side-note, it looks like other people seem to build the whole CSV
as a string and then ship it at the end. Maybe my strategy results in
the same behaviour under Rails unless I explicitly flush it somehow,
in which case maybe I should just copy what everyone else is doing...

TX