Hi there! as some of you may know, I've been working on an aarch64 native code generator. Now I've hit a situation where my stage2 compiler somehow corrupts my heap. Initially I thought this would likely be missing memory barriers, however they are emitted. This doesn't mean it can't be, but at least it's not as simple as "they are just missing". The crashes I see are non deterministic, in fact I sometimes even manage to compile a Hello World module, without crashes. Other times it crashes with unknown closure errors or it just crashes. But it always crashes during GC. Changing the nursery size make it crasha bit more frequent, but nothing obvious sticks out yet. If anyone has some create ideas, I'd love to hear them. I've been wondering if just logging allocations (offset, range, type) would help figuring out what we expected to be there; and then maybe try to break on the allocation, (and subsequent writes). I'm sure some have been down this road before. Cheers, Moritz