From 6dfed31c4313c1eee7b1aa155e0761c5cdf7f128 Mon Sep 17 00:00:00 2001
From: Fabian Wolff <fabian.wolff@alumni.ethz.ch>
Date: Sat, 27 Nov 2021 18:42:49 +0100
Subject: [PATCH] Improve error message for `E0659` if the source is not
 available

---
 compiler/rustc_resolve/src/diagnostics.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 2e4cb4ff7270d..6a13627a56314 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -1178,7 +1178,7 @@ impl<'a> Resolver<'a> {
 
     fn binding_description(&self, b: &NameBinding<'_>, ident: Ident, from_prelude: bool) -> String {
         let res = b.res();
-        if b.span.is_dummy() {
+        if b.span.is_dummy() || self.session.source_map().span_to_snippet(b.span).is_err() {
             // These already contain the "built-in" prefix or look bad with it.
             let add_built_in =
                 !matches!(b.res(), Res::NonMacroAttr(..) | Res::PrimTy(..) | Res::ToolMod);