Add test

diff --git a/src/test/compile-fail/issue-6596.rs b/src/test/compile-fail/issue-6596.rs
new file mode 100644 (file)
index 0000000..3c952db
--- /dev/null
+++ b/src/test/compile-fail/issue-6596.rs
@@ -0,0 +1,9 @@
+macro_rules! e( //~ ERROR unknown macro variable `nonexistent`
+    ($inp:ident) => (
+        $nonexistent
+    );
+)
+
+fn main() {
+    e!(foo);
+}