I installed Rust at home with no issues. Behind a company proxy I couldn't run rustup-init, so I installed 1.18 stable with an installer.
On every Rust command (e.g. cargo). I get the notification "error: no default toolchain configured". The only related question I found was this one, but the answer isn't very helpful. Knowing it is a proxy issue is useful, but I can't find an answer how to configure the proxy so that this works.