How to invoke rules_rust toolchain rustc via the command line?

[samuela]

Supposing I have a toolchain set up with eg

# WORKSPACE
rust_register_toolchains(
    edition = "2021",
    extra_target_triples = [],
    urls = ["https://foo.com/{}.tar.gz"],
    versions = ["1.66.1"],
)

How can I invoke this toolchain's rustc via the command line? For example, something like

bazel run @rules_rust//tools/rustc -- --version

[UebelAndre]

There isn't really a fantastic way, you'd need to know what toolchain you matched. There's @rules_rust//rust/toolchain:current_rustc_files but that's not executable. It might be reasonable to do so but building that target should force bazel to download a compiler where you can find it in the Bazel output base for your checkout.

[samuela]

Is the compiler downloaded to a stable location? Could that potentially be a workaround?