From 4f4391193cca2f7a28d351947e12f954d9432693 Mon Sep 17 00:00:00 2001
From: Guillaume Maudoux <layus.on@gmail.com>
Date: Sun, 10 Mar 2019 00:45:55 +0100
Subject: [PATCH] Fix warning about unused variable

---
 src/nix-daemon/nix-daemon.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/nix-daemon/nix-daemon.cc b/src/nix-daemon/nix-daemon.cc
index 63b5eb87d..0feafb013 100644
--- a/src/nix-daemon/nix-daemon.cc
+++ b/src/nix-daemon/nix-daemon.cc
@@ -477,11 +477,13 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         Roots roots = store->findRoots();
         logger->stopWork();
+
+        // Pre-compute roots length using same algo as below.
         size_t total_length = 0;
         bool hasMemoryLink;
-        for (auto & [target, links] : roots) {
+        for (auto & root : roots) {
             hasMemoryLink = false;
-            for (auto & link : links) {
+            for (auto & link : root.second) {
                 if (link.rfind("{memory:", 0) == 0) {
                     if (hasMemoryLink) continue;
                     ++total_length;
@@ -491,6 +493,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
                 }
             }
         }
+
         to << total_length;
         int n = 0;
         for (auto & [target, links] : roots) {