My problem at the moment is with Apple upgrading my system - so the steps in https://developer.holochain.org/docs/install/ no longer seem to work (coincidently neither does my old 32 bit Adobe software and a few other things).
There are quite a few new things for me to get my head around Xcode (Installed OK), Nix (needs more work), Rust (at least it is there to read about).
Apple OS Catalina is not helping!