Also, aarch64 Haskell is almost exclusively not in production (although there's probably some iOS/macOS apps out there - very cool if so!). This bug shows up on devs' M1 MBPs and the CI used to build their Nix cache.

It's a nasty bug, but in reality it isn't some P0 monstrosity despite how "eXtReMeLy aLaRmInG" it seems.