v/vlib/v/checker/tests/for_in_index_optional.out

vlib/v/checker/tests/for_in_index_optional.vv:3:18: error: for in: cannot index `?[]string`
    1 | import os
    2 | fn main() {
    3 |   for file in os.ls('.') {
      |                  ~~~~~~~
    4 |     println(file)
    5 |   }