From 9.12, -fobject-determinism[1] will guarantee deterministic objects. If it ever doesn't, do open a bug report[2] [1] https://downloads.haskell.org/ghc/lat

From 9.12, -fobject-determinism[1] will guarantee deterministic objects. If it ever doesn't, do open a bug report[2] [1] https://downloads.haskell.org/ghc/latest/docs/users_guide/using-optimisation.html#ghc-flag-fobject-determinism https://downloads.haskell.org/ghc/latest/docs/users_guide/us... [2] https://gitlab.haskell.org/ghc/ghc/-/issues https://gitlab.haskell.org/ghc/ghc/-/issues