1 files changed, 25 insertions, 0 deletions
diff --git a/src/test/ui/traits/trait-upcasting/migrate-lint-deny.rs b/src/test/ui/traits/trait-upcasting/migrate-lint-deny.rs
new file mode 100644
index 000000000..c67251018
--- /dev/null
+++ b/src/test/ui/traits/trait-upcasting/migrate-lint-deny.rs
@@ -0,0 +1,25 @@
+#![deny(deref_into_dyn_supertrait)]
+
+extern crate core;
+
+use core::ops::Deref;
+
+// issue 89190
+trait A {}
+trait B: A {}
+impl<'a> Deref for dyn 'a + B {
+    type Target = dyn A;
+    fn deref(&self) -> &Self::Target {
+        todo!()
+    }
+}
+
+fn take_a(_: &dyn A) {}
+
+fn whoops(b: &dyn B) {
+    take_a(b)
+    //~^ ERROR `dyn B` implements `Deref` with supertrait `(dyn A + 'static)` as output
+    //~^^ WARN this was previously accepted by the compiler but is being phased out;
+}
+
+fn main() {}