error: the error slot of a failable cannot be dropped — bind it (`v, err := …`) and handle it, or use `try` / `catch`
  --> examples/1019-errors-failable-discard-reject.sx:27:13
   |
27 |     a, b := pair(5);     // ERROR: error slot omitted (3 slots, 2 names)
   |             ^^^^^^^

error: the error slot of a failable cannot be dropped — bind it (`v, err := …`) and handle it, or use `try` / `catch`
  --> examples/1019-errors-failable-discard-reject.sx:28:13
   |
28 |     v, _ := parse(5);    // ERROR: error slot discarded with `_`
   |             ^^^^^^^^