def cargo_target_path(target, *path_components)
      target_base = ENV.fetch('CARGO_TARGET_DIR', File.join(rust_toplevel_dir, 'target'))
      File.join(target_base, target, *path_components)
    end
def cargo_target_path(target, *path_components)
      target_base = ENV.fetch('CARGO_TARGET_DIR', File.join(rust_toplevel_dir, 'target'))
      File.join(target_base, target, *path_components)
    end
Generate a path relative to the `CARGO_TARGET_DIR` environment variable, or
 {#rust_toplevel_dir}/target if that is not set.