src/test/ui/proc-macro/non-root.stderr

error: functions tagged with `#[proc_macro]` must currently reside in the root of the crate
  --> $DIR/non-root.rs:11:5
   |
LL |     pub fn foo(arg: TokenStream) -> TokenStream { arg }
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error