GHC 9.6.3 intermittently crashes non-deterministically while compiling large code base

A client has an application which crashes GHC 9.6.3 non-deterministically with either a SIGSEGV or SIGBUS. Unfortunately this is quite tricky to reproduce. The program in question is being compiled with parallel compilation on an AArch64 (Graviton 2) machine running Ubuntu 22.04. I have reproduced the crash using both the upstream GHC 9.6.3 bindist and my own build. However, I have yet to observe the issue when compiling ghc against the -debug RTS.

Edited Dec 12, 2023 by Ben Gamari

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