Question: I installed rustup with brew command but still says that rustup command is not found. I am not sure if I am missing any installation step. Any help would be appreciated.

Answer: 
To configure your current shell, run

```
source $HOME/.cargo/env 

```

this command FINALLY completed the painful installation of Rust.
I had the same problem, because the PATH variable didn't include the Cargo's bin directory right after installation.

I closed and opened again the shell, and it worked!