error: duplicate item `dup` in service `Service1`
  ╭▸ test/ui/duplicate_service_item.aldrin:7:8
  │
7 │     fn dup = fallback;
  │        ━━━ duplicate defined here
  │
  ⸬  test/ui/duplicate_service_item.aldrin:5:8
  │
5 │     fn dup @ 1;
  ╰╴       ─── first defined here