message: Make the empty rustc-wrapper test more explicit.
diff: @@ -870,7 +870,18 @@ fn check_keep_going() {
  #[cargo_test]
  fn does_not_use_empty_rustc_wrapper() {
  - let p = project().file("src/lib.rs", "").build();
  + // An empty RUSTC_WRAPPER environment variable won't be used.
  + // The env var will also override the config, essentially unsetting it.
  + let p = project()
  + .file("src/lib.rs", "")
  + .file(
  + ".cargo/config.toml",
  + r#"
  + [build]
  + rustc-wrapper = "do-not-execute-me"
  + "#,
  + )
  + .build();
  p.cargo("check").env("RUSTC_WRAPPER", "").run();
  }
  