Explain iterator invalidation on borrow error when trying to modify currently looping vec

[estebank]

Code

fn main() {
    let mut values = vec![1, 2, 3];

    // The diagnostic identifies the conflicting borrows, but does not explain
    // that the loop keeps `values` borrowed for the iteration or give any
    // beginner-facing guidance about restructuring the operation.
    for value in &values {
        if *value == 2 {
            values.push(4);
            //~^ ERROR cannot borrow `values` as mutable because it is also borrowed as immutable
        }
    }
}

Current output

error[E0502]: cannot borrow `values` as mutable because it is also borrowed as immutable
  --> $DIR/mutate-vec-while-iterating.rs:12:13
   |
LL |     for value in &values {
   |                  -------
   |                  |
   |                  immutable borrow occurs here
   |                  immutable borrow later used here
LL |         if *value == 2 {
LL |             values.push(4);
   |             ^^^^^^^^^^^^^^ mutable borrow occurs here

Desired output

It should explain iterator invalidation and render in a more pedagogical way.

Rationale and extra context

No response

Other cases

Rust Version

1.97

Anything else?

No response