fix(resolve): not defined `extern crate shadow_name`

2 files changed, 6 insertions, 1 deletions

diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index 08b73ebb694..b3d0e4ba258 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -873,6 +873,11 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                     let msg = "macro-expanded `extern crate` items cannot \
                                        shadow names passed with `--extern`";
                     self.r.tcx.sess.span_err(item.span, msg);
+                    // `return` is intended to discard this binding because it's an
+                    // unregistered ambiguity error which would result in a panic
+                    // caused by inconsistency `path_res`
+                    // more details: https://github.com/rust-lang/rust/pull/111761
+                    return;
                 }
             }
             let entry = self.r.extern_prelude.entry(ident.normalize_to_macros_2_0()).or_insert(
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 3cdc3f0ecf8..1e31a0ff278 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -106,7 +106,7 @@ impl Determinacy {
 /// A specific scope in which a name can be looked up.
 /// This enum is currently used only for early resolution (imports and macros),
 /// but not for late resolution yet.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 enum Scope<'a> {
     DeriveHelpers(LocalExpnId),
     DeriveHelpersCompat,