My biggest problem is slow linking. Even if I only change a single file, I have to wait 5-10 seconds just for the linker. I was excited to try out faster lld linking, but none of the recommended lines worked (on x86_64-pc-windows-gnu).

The RUSTFLAGS failed with

error: failed to run `rustc` to learn about target-specific information

Caused by:
  process didn't exit successfully: `rustc - --crate-name ___ --print=file-names "\"-C" "link-arg=-fuse-ld=lld\"" --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=cfg` (exit code: 1)
  --- stderr
  error: multiple input filenames provided (first two filenames are `-` and `"-C`)

Looks like there’s some escaping stuff going on when you do it on Windows.

The Cargo.toml flags failed with unused manifest key warnings:

warning: unused manifest key: target.x86_64-pc-windows-gnu.linker
warning: unused manifest key: target.x86_64-unknown-linux-gnu.linker

Not sure if I’m doing anything wrong or if the guide recommends things that weren’t tested at all.

(EDIT: The tutorial is wrong. These keys have to be added to config.toml, not Cargo.toml. Now it cannot find lld but that’s already progress.)