limit to 2018 edition

diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index b3aadf4dc72e72218d034443d0359520cb73aa96..6bbe31564a35a6069c015b2aa57fc113de1f06db 100644 (file)
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -4304,6 +4304,7 @@ fn lookup_import_candidates_from_module<FilterFn>(&mut self,
 
                     let is_extern_crate_that_also_appears_in_prelude =
                         name_binding.is_extern_crate() &&
+                        self.session.rust_2018() &&
                         self.extern_prelude.contains(&ident.name);
 
                     let is_visible_to_user =