Release build errors triggered by optimizations

[ultrabug]

Hi,

I'm trying to find out why I'm getting ConvertToUtf8 and ConvertI64ToUsize deserialization errors when running in release mode while I'm not getting them on debug mode.

For now, I pinned down the fact that if I disable optimizations in the release profile, the errors go away:

[profile.release]
opt-level = 0

Does that ring a bell to anyone?

What can I do to help debug this please?

Thanks