rules_rust manages versions of things like rustc. If you want to manually run upstream tooling configured at the versions, plugins and such that rules_rust has configured, rules_rust exposes these as targets in @rules_rust//tools/upstream_wrapper:
% bazel query @rules_rust//tools/upstream_wrapper @rules_rust//tools/upstream_wrapper:cargo @rules_rust//tools/upstream_wrapper:cargo_clippy @rules_rust//tools/upstream_wrapper:rustc @rules_rust//tools/upstream_wrapper:rustfmt
You can run them via bazel run, e.g. bazel run @rules_rust//tools/upstream_wrapper:cargo -- check.