message: Avoid coercing path to string for windows
diff: @@ -183,33 +183,26 @@ fn custom_build_env_var_rustflags() {
  fn custom_build_env_var_rustc_wrapper() {
  let wrapper = tools::echo_wrapper();
  let p = project()
  - .file(
  - ".cargo/config",
  - &format!(
  - r#"
  - [build]
  - rustc-wrapper = "{}"
  - "#,
  - wrapper.display()
  - ),
  - )
  .file(
  "build.rs",
  - &format!(
  r#"
  use std::env;
  fn main() {{
  - assert!(env::var("CARGO_RUSTC_WRAPPER").unwrap().ends_with("{}"));
  + assert_eq!(
  + env::var("CARGO_RUSTC_WRAPPER").unwrap(),
  + env::var("CARGO_RUSTC_WRAPPER_CHECK").unwrap()
  + );
  }}
  "#,
  - wrapper.display()
  - ),
  )
  .file("src/lib.rs", "")
  .build();
  - p.cargo("check").run();
  + p.cargo("check")
  + .env("CARGO_BUILD_RUSTC_WRAPPER", &wrapper)
  + .env("CARGO_RUSTC_WRAPPER_CHECK", &wrapper)
  + .run();
  }
  #[cargo_test]
  