From e55c48c564ad7fa8576fe3b49bba2a490f6e7a63 Mon Sep 17 00:00:00 2001
From: Christian Hesse <mail@eworm.de>
Date: Wed, 6 May 2026 15:01:36 +0200
Subject: [PATCH] make the build (man page) reproducible

---
 config.mk | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/config.mk b/config.mk
index 5cad7038..ef1edc8a 100644
--- a/config.mk
+++ b/config.mk
@@ -104,7 +104,11 @@ else
 	MAN_INOTIFY = disabled
 endif
 
-MAN_DATE ?= ${shell date '+%B %d, %Y'}
+# The environment variable SOURCE_DATE_EPOCH is used by build environments
+# to produce reproducible binary builds. In fact you can set both manually,
+# SOURCE_DATE_EPOCH and MAN_DATE.
+SOURCE_DATE_EPOCH ?= $(shell date +%s)
+MAN_DATE ?= ${shell date --utc --date=@$(SOURCE_DATE_EPOCH) '+%B %d, %Y'}
 
 # Uncomment this to use dmalloc
 #CFLAGS += -DWITH_DMALLOC