warning: the feature `crate_in_paths` has been stable since 1.30.0 and no longer requires an attribute to enable
  --> $DIR/dollar-crate-modern.rs:6:24
   |
LL | #![feature(decl_macro, crate_in_paths)]
   |                        ^^^^^^^^^^^^^^
   |
   = note: #[warn(stable_features)] on by default