In the words of @andreasabel [here](https://github.com/haskell/happy/issues/24#issuecomment-2349194443): Put a long list of warning flags like {-# OPTIONS_GHC -Wwarn-tabs #-} in the preamble that we know we wouldn't trigger. I voiced my concerns about lacking compatibility with future GHC versions [here](https://github.com/haskell/happy/issues/24#issuecomment-2348533530).