tests/ui/array-slice-vec/vec-mut-iter-borrow.stderr

error[E0499]: cannot borrow `xs` as mutable more than once at a time
  --> $DIR/vec-mut-iter-borrow.rs:5:9
   |
LL |       for x in &mut xs {
   |       -        -------
   |       |        |
   |       |        first mutable borrow occurs here
   |  _____|        first borrow later used here
   | |
LL | |         xs.push(1)
   | |         ^^ second mutable borrow occurs here
LL | |     }
   | |_____- this for loop borrows `xs` mutably, preventing mutation within its body
   |
   = help: consider using an index-based loop instead, or collecting modifications into a separate collection

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0499`.