From ea4154df80861c5d84708c186fb6389cea896819 Mon Sep 17 00:00:00 2001
From: Simon Mo <simon.mo@hey.com>
Date: Fri, 5 Feb 2021 16:07:45 -0800
Subject: [PATCH] [Hotfix] Master compilation error on MacOS. (#13946)

---
 src/ray/core_worker/reference_count.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ray/core_worker/reference_count.cc b/src/ray/core_worker/reference_count.cc
index a38a98d80..db05320a9 100644
--- a/src/ray/core_worker/reference_count.cc
+++ b/src/ray/core_worker/reference_count.cc
@@ -1010,7 +1010,7 @@ void ReferenceCounter::PushToLocationSubscribers(ReferenceTable::iterator it) {
   const auto callbacks = it->second.location_subscription_callbacks;
   it->second.location_subscription_callbacks.clear();
   it->second.location_version++;
-  for (const auto callback : callbacks) {
+  for (const auto &callback : callbacks) {
     callback(it->second.locations, it->second.object_size, it->second.location_version);
   }
 }