error: duplicate variant `Var` in enum `Enum`
  ╭▸ test/ui/duplicate_enum_variant.aldrin:4:5
  │
4 │     Var = fallback;
  │     ━━━ duplicate defined here
  │
  ⸬  test/ui/duplicate_enum_variant.aldrin:2:5
  │
2 │     Var @ 1;
  ╰╴    ──────── first defined here