Cloning borrows to things that lack a Clone impl simply return the original borrow.

sans-clone-derive.rs

// NB. fix
// #[derive(Debug, Clone)]
#[derive(Debug)]
struct Context;

fn dupe_context(context: &Context) -> Context {
    context.clone()
}

fn main() {
    let context = Context;
    dupe_context(&context);
    dbg!(context);
}