1 files changed, 11 insertions, 2 deletions
diff --git a/compiler/rustc_middle/src/ty/diagnostics.rs b/compiler/rustc_middle/src/ty/diagnostics.rs
index b122ada0925..b3042904a29 100644
--- a/compiler/rustc_middle/src/ty/diagnostics.rs
+++ b/compiler/rustc_middle/src/ty/diagnostics.rs
@@ -7,14 +7,14 @@ use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::{
     Applicability, Diag, DiagArgValue, IntoDiagArg, into_diag_arg_using_display, listify, pluralize,
 };
-use rustc_hir::def::DefKind;
+use rustc_hir::def::{DefKind, Namespace};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{self as hir, AmbigArg, LangItem, PredicateOrigin, WherePredicateKind};
 use rustc_span::{BytePos, Span};
 use rustc_type_ir::TyKind::*;
 
 use crate::ty::{
-    self, AliasTy, Const, ConstKind, FallibleTypeFolder, InferConst, InferTy, Opaque,
+    self, AliasTy, Const, ConstKind, FallibleTypeFolder, InferConst, InferTy, Instance, Opaque,
     PolyTraitPredicate, Projection, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable,
     TypeSuperVisitable, TypeVisitable, TypeVisitor,
 };
@@ -28,6 +28,15 @@ impl IntoDiagArg for Ty<'_> {
     }
 }
 
+impl IntoDiagArg for Instance<'_> {
+    fn into_diag_arg(self, path: &mut Option<std::path::PathBuf>) -> rustc_errors::DiagArgValue {
+        ty::tls::with(|tcx| {
+            let instance = tcx.short_string_namespace(self, path, Namespace::ValueNS);
+            rustc_errors::DiagArgValue::Str(std::borrow::Cow::Owned(instance))
+        })
+    }
+}
+
 into_diag_arg_using_display! {
     ty::Region<'_>,
 }