1 files changed, 68 insertions, 0 deletions
diff --git a/src/test/ui/specialization/specialization-no-default.stderr b/src/test/ui/specialization/specialization-no-default.stderr
new file mode 100644
index 000000000..28c869a70
--- /dev/null
+++ b/src/test/ui/specialization/specialization-no-default.stderr
@@ -0,0 +1,68 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/specialization-no-default.rs:1:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+
+error[E0520]: `foo` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-no-default.rs:20:5
+   |
+LL | impl<T> Foo for T {
+   | ----------------- parent `impl` is here
+...
+LL |     fn foo(&self) {}
+   |     ^^^^^^^^^^^^^^^^ cannot specialize default item `foo`
+   |
+   = note: to specialize, `foo` in the parent `impl` must be marked `default`
+
+error[E0520]: `bar` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-no-default.rs:23:5
+   |
+LL | impl<T> Foo for T {
+   | ----------------- parent `impl` is here
+...
+LL |     fn bar(&self) {}
+   |     ^^^^^^^^^^^^^^^^ cannot specialize default item `bar`
+   |
+   = note: to specialize, `bar` in the parent `impl` must be marked `default`
+
+error[E0520]: `T` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-no-default.rs:37:5
+   |
+LL | impl<T> Bar for T {
+   | ----------------- parent `impl` is here
+...
+LL |     type T = ();
+   |     ^^^^^^^^^^^^ cannot specialize default item `T`
+   |
+   = note: to specialize, `T` in the parent `impl` must be marked `default`
+
+error[E0520]: `baz` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-no-default.rs:55:5
+   |
+LL | impl<T: Clone> Baz for T {
+   | ------------------------ parent `impl` is here
+...
+LL |     fn baz(&self) {}
+   |     ^^^^^^^^^^^^^^^^ cannot specialize default item `baz`
+   |
+   = note: to specialize, `baz` in the parent `impl` must be marked `default`
+
+error[E0520]: `redundant` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/specialization-no-default.rs:74:5
+   |
+LL | impl<T: Clone> Redundant for T {
+   | ------------------------------ parent `impl` is here
+...
+LL |     default fn redundant(&self) {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot specialize default item `redundant`
+   |
+   = note: to specialize, `redundant` in the parent `impl` must be marked `default`
+
+error: aborting due to 5 previous errors; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0520`.