It's very difficult for a broad based record/replay software like rr to exist for macOS in my opinion. macOS system interfaces are quite basic in terms of functionality compared to Linux and increasingly locked down.

rr uses many advanced features of Linux `ptrace`. Compare `man ptrace` on Linux with that on macOS for example and you will notice that Linux gives a lot of features to `ptrace` that macOS simply does not.

There are a large number of other features required for practical record and replay -- I dont think macOS simply provides them also.

It's probably possible to build _some_ record/replay system on macOS with constraints, restrictions, workarounds and compromises -- never say never as they say. But I don't think it can be as capable/generic as rr on Linux.