vlib/v/checker/tests/right_hand_side_mut.vv:4:19: error: unexpected `mut` on right-hand side of assignment
    2 |     mut flubbel := 123
    3 |     mut wubbel := 234
    4 |     _, _ := flubbel, mut wubbel
      |                      ~~~
    5 |     print(wubbel)
    6 | }
