Seems there's a compiler crash in the latest Swift 5.2 compiler.

I haven't yet tracked down exactly what the issue is, but it can be reproduced with simple code like:

import SwiftUI import Grid struct Foo: Hashable {} struct GifsView: View { var body: some View { List([Foo()], id: \.self) { _ in Text("") } .gridStyle(ModularGridStyle(columns: 1, rows: 1)) } }

So it's definitely something in .gridStyle or GridStyle.

You can also reproduce the crash by opening the Xcode project in this repo, selecting the "GridDemo macOS" target and and then selecting the "Product => Archive" menu item.

I would recommend getting this project added to https://github.com/apple/swift-source-compat-suite