1 files changed, 22 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-51154.stderr b/src/test/ui/issues/issue-51154.stderr
new file mode 100644
index 000000000..44ec626de
--- /dev/null
+++ b/src/test/ui/issues/issue-51154.stderr
@@ -0,0 +1,22 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-51154.rs:2:30
+   |
+LL | fn foo<F: FnMut()>() {
+   |        - this type parameter
+LL |     let _: Box<F> = Box::new(|| ());
+   |                     -------- ^^^^^ expected type parameter `F`, found closure
+   |                     |
+   |                     arguments to this function are incorrect
+   |
+   = note: expected type parameter `F`
+                     found closure `[closure@$DIR/issue-51154.rs:2:30: 2:32]`
+   = help: every closure has a distinct type and so could not always match the caller-chosen type of parameter `F`
+note: associated function defined here
+  --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
+   |
+LL |     pub fn new(x: T) -> Self {
+   |            ^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.