1 files changed, 19 insertions, 0 deletions
diff --git a/src/test/ui/nll/issue-54943-3.rs b/src/test/ui/nll/issue-54943-3.rs
new file mode 100644
index 000000000..077eb1563
--- /dev/null
+++ b/src/test/ui/nll/issue-54943-3.rs
@@ -0,0 +1,19 @@
+// check-pass
+// FIXME(#54943) This test targets the scenario where proving the WF requirements requires
+// knowing the value of the `_` type present in the user type annotation - unfortunately, figuring
+// out the value of that `_` requires type-checking the surrounding code, but that code is dead,
+// so our NLL region checker doesn't have access to it. This test should actually fail to compile.
+
+#![allow(warnings)]
+
+use std::fmt::Debug;
+
+fn foo<T: 'static + Debug>(_: T) { }
+
+fn bar<'a>() {
+    return;
+
+    let _x = foo::<Vec<_>>(Vec::<&'a u32>::new());
+}
+
+fn main() {}