1 files changed, 26 insertions, 0 deletions
diff --git a/src/test/ui/closures/2229_closure_analysis/issue-87378.rs b/src/test/ui/closures/2229_closure_analysis/issue-87378.rs
new file mode 100644
index 000000000..75901a571
--- /dev/null
+++ b/src/test/ui/closures/2229_closure_analysis/issue-87378.rs
@@ -0,0 +1,26 @@
+#![feature(rustc_attrs)]
+
+// edition:2021
+
+// Test that any precise capture on a union is truncated because it's unsafe to do so.
+
+union Union {
+    value: u64,
+}
+
+fn main() {
+    let u = Union { value: 42 };
+
+    let c = #[rustc_capture_analysis]
+    //~^ ERROR: attributes on expressions are experimental
+    //~| NOTE: see issue #15701 <https://github.com/rust-lang/rust/issues/15701>
+    || {
+    //~^ ERROR: First Pass analysis includes:
+    //~| ERROR: Min Capture analysis includes:
+       unsafe { u.value }
+        //~^ NOTE: Capturing u[(0, 0)] -> ImmBorrow
+        //~| NOTE: Min Capture u[] -> ImmBorrow
+    };
+
+    c();
+}