crates_vendor target in the BUILD.bazel from this directory is used in fx update-rustc-third-party to generate Bazel target for Rust libraries in //third_party/rust_crates.
Always use fx update-rustc-third-party instead of building of this target directly. The targets defined in BUILD.bazel rely on a temporary Bazel workspace constructed in update-rustc-third-party, so building it directly won't work.
This setup uses the following vendored/prebuilt tools:
Bazel will fetch other dependencies from upstream, this includes Rust crates needed to bootstrap crates_vendor (build the cargo_bazel binary).
This only supports running on Linux hosts.