message: more comment
diff: @@ -502,7 +502,8 @@ fn inside_cargo_rustc() {
  ///
  /// Currently, we detect this by checking for "--target=", which is
  /// never set for host crates. This matches what rustc bootstrap does,
  - /// which hopefully makes it "reliable enough".
  + /// which hopefully makes it "reliable enough". This relies on us always
  + /// invoking cargo itself with `--target`, which `in_cargo_miri` ensures.
  fn is_target_crate() -> bool {
  get_arg_flag_value("--target").is_some()
  }
  