From a2066d75f9cf46ca98d137b61789d12daef677e1 Mon Sep 17 00:00:00 2001
From: skshetry <18718008+skshetry@users.noreply.github.com>
Date: Fri, 17 Mar 2023 17:52:04 +0545
Subject: [PATCH] add a note why we are flushing (#9205)

---
 dvc/daemon.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/dvc/daemon.py b/dvc/daemon.py
index 874627e43..7caf42d44 100644
--- a/dvc/daemon.py
+++ b/dvc/daemon.py
@@ -56,6 +56,8 @@ def _spawn_windows(cmd, env):
 def _spawn_posix(cmd, env):
     from dvc.cli import main
 
+    # `fork` will copy buffers, so we need to flush them before forking.
+    # Otherwise, we will get duplicated outputs.
     if sys.stdout and not sys.stdout.closed:
         sys.stdout.flush()
     if sys.stderr and not sys.stderr.closed: