More importantly, the llvm libunwind is also missing the dynamic unwind info registration functions so we can’t use it as it. Having to support multiple libunwind is obviously not ideal although not too bad either given that they have similar api. IMO, the best way forward (and we are inevitably doing already) is to take over libunwind and merge all the patches that we need. Ideally we should also check with a few other projects that maintain their own libunwind forks.