message: build libstd with minimal features
diff: @@ -155,6 +155,9 @@ fn setup(ask_user: bool) {
  File::create(dir.join("Xargo.toml")).unwrap()
  .write_all(br#"
  [dependencies.std]
  +default_features = false
  +# We need the `panic_unwind` feature because we use the `unwind` panic strategy.
  +# Using `abort` works for libstd, but then libtest will not compile.
  features = ["panic_unwind"]
  [dependencies.test]
  