Here's how to get your environment set up to:
- Develop iOS and Android apps using Rust.
- Enable GUI debugging of Rust projects in Xcode.
If you just want to enable GUI debugging of macOS Rust projects in Xcode, I'm not actually sure whether you need cargo-mobile at all. But one benefit of installing it is that it automatically installs rust-xcode-plugin for you, giving you syntax highlighting of Rust sources in Xcode.