use sealed::sealed;

mod lets {
    pub mod attempt {
        pub mod some {
            pub mod nesting {
                use sealed::sealed;
                #[sealed(pub(crate))]
                pub trait T {}
            }
        }
    }
}

pub struct A;
pub struct B {
    field_1: i32,
}
pub struct C;

#[sealed]
impl lets::attempt::some::nesting::T for A {}
#[sealed]
impl lets::attempt::some::nesting::T for B {}
// fails to compile
impl lets::attempt::some::nesting::T for C {}

fn main() {}