Double free error?

This is one of the memory safety bugs in Rust, which we will try to understand through a dialogue in this blog post.

let s1 = String::from("Hello");
let s2 = s1;

let s1 = String::from("Hello");
let s2 = s1;
println!("{}", s1);

Error — use of moved value s1

Do share your understanding.

Thanks!