From 4769eea5e2229c01c3b5d050891b071a45a024d5 Mon Sep 17 00:00:00 2001
From: Daiderd Jordan <daiderd@gmail.com>
Date: Sat, 2 May 2020 23:26:12 +0200
Subject: [PATCH] logging: handle build log lines in simple logger

The raw stderr output isn't logged anymore so the build logs need to be
printed by the default logger in order for the old commands like
nix-build to still show build output.
---
 src/libutil/logging.cc | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/libutil/logging.cc b/src/libutil/logging.cc
index 3cc4ef8f1..777650de5 100644
--- a/src/libutil/logging.cc
+++ b/src/libutil/logging.cc
@@ -63,6 +63,16 @@ public:
         writeToStderr(prefix + filterANSIEscapes(fs.s, !tty) + "\n");
     }
 
+    void result(ActivityId act, ResultType type, const std::vector<Field> & fields) override
+    {
+        if (type == resBuildLogLine || type == resPostBuildLogLine) {
+            assert(0 < fields.size());
+            assert(fields[0].type == Logger::Field::tString);
+            auto lastLine = fields[0].s;
+            log(lvlInfo, lastLine);
+        }
+    }
+
     void startActivity(ActivityId act, Verbosity lvl, ActivityType type,
         const std::string & s, const Fields & fields, ActivityId parent)
         override