From 13f97e09e822a9130f1e07947b84dcd2f932d57d Mon Sep 17 00:00:00 2001
From: Zenong Zhang <41390071+SlaterLatiao@users.noreply.github.com>
Date: Fri, 29 Jul 2022 13:07:00 -0700
Subject: [PATCH] Added back error message on action stack. (#1826)

---
 explorer/interpreter/action_stack.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/explorer/interpreter/action_stack.cpp b/explorer/interpreter/action_stack.cpp
index 7f24d7ecb181..24792210872b 100644
--- a/explorer/interpreter/action_stack.cpp
+++ b/explorer/interpreter/action_stack.cpp
@@ -131,6 +131,7 @@ auto ActionStack::FinishAction() -> ErrorOr<Success> {
     case Action::Kind::ExpressionAction:
     case Action::Kind::LValAction:
     case Action::Kind::PatternAction:
+      CARBON_FATAL() << "This kind of action must produce a result: " << *act;
     case Action::Kind::ScopeAction:
       CARBON_FATAL() << "ScopeAction at top of stack";
     case Action::Kind::StatementAction: