message: Ensure RUSTC_WRAPPER isn't set if no wrapper is used
diff: @@ -252,6 +252,8 @@ fn build_work(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Job> {
  // Also inform the build script of the rustc compiler context.
  if let Some(wrapper) = bcx.rustc().wrapper.as_ref() {
  cmd.env("RUSTC_WRAPPER", wrapper);
  + } else {
  + cmd.env_remove("RUSTC_WRAPPER");
  }
  cmd.env("RUSTFLAGS", bcx.rustflags_args(unit).join(" "));
  let version = crate::version();
  