error: duplicate field `field` in struct `Struct`
  --> test/ui/duplicate_struct_field.aldrin:3:5
   |
 3 |     field @ 2 = i32;
   |     ^^^^^ duplicate defined here
   |
  ::: test/ui/duplicate_struct_field.aldrin:2:5
   |
 2 |     field @ 1 = i32;
   |     ----- first defined here
   |
