Trouble with accessibility and GtkTreeViewColumn with multiple cells

[Dylan McCall <dylanmccall gmail com>]

I have a GtkTreeViewColumn with three cell renderers: a toggle, an
image and a label. This renders nicely, but Orca only reads the last
item in the column: the label. I need it to read the checkbox as well.
How can I go about making that happen?

Here's a snippet of code, for context. (I'm using Python with PyGObject):

    pkg_column = Gtk.TreeViewColumn()
    pkg_column.set_title(_("Install"))
    pkg_column.set_property("spacing", 4)

    pkg_toggle_renderer = Gtk.CellRendererToggle()
    pkg_toggle_renderer.set_property("ypad", 2)
    pkg_toggle_renderer.connect("toggled", self.on_update_toggled)
    pkg_column.pack_start(pkg_toggle_renderer, False)
    pkg_column.add_attribute(pkg_toggle_renderer, 'active', LIST_TOGGLE_ACTIVE)
    #pkg_column.set_cell_data_func(pkg_toggle_renderer,
self.pkg_toggle_renderer_view_func)

    pkg_icon_renderer = Gtk.CellRendererPixbuf()
    pkg_icon_renderer.set_property("ypad", 2)
    pkg_icon_renderer.set_property("stock-size", Gtk.IconSize.MENU)
    pkg_column.pack_start(pkg_icon_renderer, False)
    pkg_column.set_cell_data_func(pkg_icon_renderer,
self.pkg_icon_renderer_view_func)

    pkg_label_renderer = Gtk.CellRendererText()
    pkg_label_renderer.set_property("ypad", 2)
    pkg_column.pack_start(pkg_label_renderer, True)
    pkg_column.set_cell_data_func(pkg_label_renderer,
self.pkg_label_renderer_view_func)

    pkg_column.set_sizing(Gtk.TreeViewColumnSizing.FIXED)
    pkg_column.set_expand(True)
    self.treeview_update.append_column(pkg_column)

Thank you!

Dylan