From 0a2545f95c155588a82f0e112aa1e8853e58477d Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Wed, 5 Sep 2018 21:35:58 +0200
Subject: [PATCH] Log stats to stderr

We shouldn't pollute stdout.
---
 src/libexpr/eval.cc | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index a67b7ae0d..08a2c2bfc 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -26,8 +26,6 @@
 
 #endif
 
-using std::cout;
-
 namespace nix {
 
 
@@ -1746,14 +1744,11 @@ void EvalState::printStats()
     GC_get_heap_usage_safe(&heapSize, 0, 0, 0, &totalBytes);
 #endif
     if (showStats) {
-        printMsg(v, "evaluation statistics:");
         auto outPath = getEnv("NIX_SHOW_STATS_PATH","-");
         std::fstream fs;
-        if (outPath != "-") {
+        if (outPath != "-")
             fs.open(outPath, std::fstream::out);
-            printMsg(v, format("  written to: %1%") % outPath);
-        }
-        JSONObject topObj(outPath == "-" ? cout : fs, true);
+        JSONObject topObj(outPath == "-" ? std::cerr : fs, true);
         topObj.attr("cpuTime",cpuTime);
         {
             auto envs = topObj.object("envs");