Diagnosing excessive memory usage / crash when compiling - 9.8.1

Hi! I'm trying to upgrade our (large) codebase to use 9.8.1. (I'm on an M2). When building with -01, memory on the GHC process climbs until it reaches the limit of my machine (64G) and then crashes with a segfault. With -00, that does not happen. How would I go about diagnosing what's happening? Using RTS flags to limit the heap to 32G produced the same behavior, just faster. Strangely, `-v5` does not produce any more output in the console (passed via cabal's --ghc-options). Maybe I'm doing it wrong? Pointers to existing issues or documentation welcome! Thank you! Justin