1 files changed, 16 insertions, 0 deletions
diff --git a/src/test/ui/borrowck/borrow-immutable-upvar-mutation-impl-trait.stderr b/src/test/ui/borrowck/borrow-immutable-upvar-mutation-impl-trait.stderr
new file mode 100644
index 00000000000..003c40d2773
--- /dev/null
+++ b/src/test/ui/borrowck/borrow-immutable-upvar-mutation-impl-trait.stderr
@@ -0,0 +1,16 @@
+error[E0594]: cannot assign to `x`, as it is a captured variable in a `Fn` closure
+  --> $DIR/borrow-immutable-upvar-mutation-impl-trait.rs:11:9
+   |
+LL |   fn bar() -> impl Fn() -> usize {
+   |      ---      ------------------ change this to return `FnMut` instead of `Fn`
+LL |       let mut x = 0;
+LL | /     move || {
+LL | |         x += 1;
+   | |         ^^^^^^ cannot assign
+LL | |         x
+LL | |     }
+   | |_____- in this closure
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0594`.