AsyncImage returning Unknown Context error

Hello.

On Xcode 15 I am trying to use AsyncImage to display an image from a URL. Whey I try, I get this in error:

The operation couldn't be completed. (SwiftUI.AsyncImage<SwiftUI._ConditionalContent <SwiftUl._ConditionalContent<SwiftUI.Text, SwiftUI.Text>, SwiftUI._ConditionalContent<SwiftUI.Text, SwiftUI.Text>>>.(unknown context at $1c552a084).LoadingError error 1.)

The view is simple, a VStack containing the AsyncImage call with a known good URL:

import SwiftUI

struct SetRowView: View {
    var set: MagicSet
    
    var body: some View {
        VStack {
            AsyncImage(url: URL(string: set.icon_svg_uri)) { phase in
                if let image = phase.image {
                    image
                }
                else if phase.error != nil {
                    Text(phase.error!.localizedDescription.debugDescription)
                }
            }
        }
    }
}

I've even hard-coded the URL to the image I want to load. Same result. I can't find any reference to this error at all.