1 files changed, 13 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-11515.stderr b/src/test/ui/issues/issue-11515.stderr
new file mode 100644
index 000000000..17bfae2a4
--- /dev/null
+++ b/src/test/ui/issues/issue-11515.stderr
@@ -0,0 +1,13 @@
+error[E0658]: cannot cast `dyn Fn()` to `dyn FnMut()`, trait upcasting coercion is experimental
+  --> $DIR/issue-11515.rs:9:33
+   |
+LL |     let test = box Test { func: closure };
+   |                                 ^^^^^^^
+   |
+   = note: see issue #65991 <https://github.com/rust-lang/rust/issues/65991> for more information
+   = help: add `#![feature(trait_upcasting)]` to the crate attributes to enable
+   = note: required when coercing `Box<(dyn Fn() + 'static)>` into `Box<(dyn FnMut() + 'static)>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.