Sigh. Alright. You get this error because some HA core component uses code written in Rust. And it needs a Rust compiler to compile it. And you don’t have that. The latest HA core will not function without a Rust compiler. So you need to install one.
That compiler needs to be available from the user you run hass as. That’s extremely important. Open a console and switch to the user you created for running hass. If you followed the tutorial above, that would be the homeassistant user.
sudo -u homeassistant -H -s
Now try to run the Rust compiler to see if it’s available.
rustc
It should say something like this:
if instead it says command not found, then you did not install Rust. Redo the steps I posted above. Do them as the user you run hass on.
Then try to run rustc again, as that user. As long as rustc doesn’t work, HA core will not work.
Edit: oh and yeah I agree, HA core is not the right install method for you. Don’t take that as an offense.