//~ ERROR cycle detected when computing layout of
//~| NOTE ...which requires computing layout of
//~| NOTE ...which again requires computing layout of

// build-fail

trait Mirror {
    type It: ?Sized;
}
impl<T: ?Sized> Mirror for T {
    type It = Self;
}
struct S(Option<<S as Mirror>::It>);

fn main() {
    //~^ NOTE cycle used when optimizing MIR for `main`
    let _s = S(None);
}