Index: clang/lib/Sema/SemaTemplateInstantiate.cpp
===================================================================
--- clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1230,8 +1230,10 @@
 
       // We recreated a local declaration, but not by instantiating it. There
       // may be pending dependent diagnostics to produce.
-      if (auto *DC = dyn_cast<DeclContext>(Old))
-        SemaRef.PerformDependentDiagnostics(DC, TemplateArgs);
+      if (auto *DC = dyn_cast<DeclContext>(Old)) {
+        if (DC->isDependentContext())
+          SemaRef.PerformDependentDiagnostics(DC, TemplateArgs);
+      }
     }
 
     /// Transform the definition of the given declaration by
Index: clang/test/SemaCXX/lambda-unevaluated.cpp
===================================================================
--- clang/test/SemaCXX/lambda-unevaluated.cpp
+++ clang/test/SemaCXX/lambda-unevaluated.cpp
@@ -122,6 +122,22 @@
 static_assert(!__is_same(decltype(foo<int>), void));
 } // namespace GH51641
 
+namespace GH57155 {
+auto foo(int t) {
+  int(*f)(int) = [](auto t) -> decltype([=] { return t; } ()) { return t; };
+  return f;
+}
+} // namespace GH57155
+
+namespace GH57170 {
+int(*f)(int) = [](auto t) -> decltype([] {
+    return 0;
+  } ()
+){
+  return t;
+};
+} // namespace GH57170
+
 namespace StaticLambdas {
 template <auto> struct Nothing {};
 Nothing<[]() static { return 0; }()> nothing;