Cargo build can't find crate for std

Hello, I'm new to rust and trying to build and flash my first program.

When I use ' cargo build --target riscv32imac-esp-espidf ' in my src folder I get this result:

I've tried ' rustup target add riscv32imac-esp-espidf ' and it does appear when I run ' rustc --print=target-list '
Any ideas why this might be happening? Thank you.

A quick search online reveals that it's a tier 3 target and doesn't come with a standard library. You have to build it yourself. I found this page: