[Flutter] Push trailing widget to bottom of Flutter Navigation Rail

How can one push the trailing widget within a Flutter Navigation Rail to the bottom of the rail? I thought it would be as simple as wrapping the trailing widget with an Expanded widget, but I get the usual flutter needs paint error message.

I can get it working if I add a Column with a first child of SizedBox with a fixed height, and then the widget I want to display, but I need the spacer to fill the available space, not a fixed height. Here's the SizedBox example which does indeed fill 200px of space, but how do I get it to fill the available space?

// other navrail properties....

trailing: Column(
children: [
SizedBox(
height: 200,
),
IconButton(icon: Icon(Icons.settings), onPressed: () {})
],
),

Continue reading...