--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/lambda-pack-init2.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,22 @@
+// PR c++/89686
+// { dg-do compile { target c++2a } }
+
+template <typename... Ts>
+void foo(Ts... xs)
+{
+  int i = 10;
+  [...xs...]{}(); // { dg-error "4:too many ..... in lambda capture" }
+  [...xs...=xs]{}(); // { dg-error "9:too many ..... in lambda capture|expected" }
+  [xs...]{}();
+  [...xs=xs]{}();
+
+  [i, ...xs...]{}(); // { dg-error "7:too many ..... in lambda capture" }
+  [i, ...xs...=xs]{}(); // { dg-error "12:too many ..... in lambda capture|expected" }
+  [i, xs...]{}();
+  [i, ...xs=xs]{}();
+}
+
+int main()
+{
+ foo(0, 1, 2);
+}