error[E0382]: borrow of moved value: `bad_letters`
  --> $DIR/issue-61108.rs:6:5
   |
LL |     let mut bad_letters = vec!['e', 't', 'o', 'i'];
   |         --------------- move occurs because `bad_letters` has type `std::vec::Vec<char>`, which does not implement the `Copy` trait
LL |     for l in bad_letters {
   |              -----------
   |              |
   |              value moved here
   |              help: consider borrowing to avoid moving into the for loop: `&bad_letters`
...
LL |     bad_letters.push('s');
   |     ^^^^^^^^^^^ value borrowed here after move

error: aborting due to previous error

For more information about this error, try `rustc --explain E0382`.