I'm currently using the No Starch book, The Rust Programming Language to learn this language. I've installed Rust and attempted to do the Hello World program but receive a command not found in zsh each time I try to compile and print to screen. I have verified that Rust is installed and that I am calling these commands from the Rust projects directory. I'm using OSX Catalina with the z shell.
Did you install rust while using the old bash terminal? If so, type "chsh -s /bin/bash" in terminal to switch back to bash shell and you will be able to use your commands.