pub fn rustup_cargo() -> Result<(PathBuf, PathBuf), String>Expand description
The rustup toolchain to use for cross-std builds (mobile targets need rustup’s target std;
a Homebrew/system rustc has none), as (cargo_path, bin_dir). The bin dir is prepended to
PATH so the toolchain’s own rustc — not one earlier on PATH — is what cargo invokes.
Overrides: RUSTUP_HOME (standard; default ~/.rustup). Among installed toolchains a
stable-* one is preferred, then the lexicographically first — deterministic where the old
first-directory-wins behavior depended on filesystem order.