File reproducible.patch of Package nvidia-modprobe

From ad60c86b625f0b7a669119b18f7a83d6a5636d48 Mon Sep 17 00:00:00 2001
From: Luca Boccassi <bluca@debian.org>
Date: Mon, 14 Mar 2022 22:28:49 +0000
Subject: [PATCH] Make the manpage build reproducible

https://reproducible-builds.org/docs/source-date-epoch/
---
 Makefile | 2 +-
 utils.mk | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 6391ca9..0406b12 100644
--- a/Makefile
+++ b/Makefile
@@ -154,7 +154,7 @@ $(OPTIONS_1_INC): $(GEN_MANPAGE_OPTS)
 $(MANPAGE_not_gzipped): nvidia-modprobe.1.m4 $(OPTIONS_1_INC) $(VERSION_MK)
 	$(call quiet_cmd,M4) -D__HEADER__=$(AUTO_TEXT) -I $(OUTPUTDIR) \
 	  -D__VERSION__=$(NVIDIA_VERSION) \
-	  -D__DATE__="`$(DATE) +%F`" \
+	  -D__DATE__=$(BUILD_DATE) \
 	  -D__BUILD_OS__=$(TARGET_OS) \
 	  $< > $@
 
diff --git a/utils.mk b/utils.mk
index f2c5cf7..973f96e 100644
--- a/utils.mk
+++ b/utils.mk
@@ -202,6 +202,14 @@ NV_QUIET_COMMAND_REMOVED_TARGET_PREFIX ?=
 
 NV_GENERATED_HEADERS ?=
 
+# Ensure the build is reproducible, for details see:
+# https://reproducible-builds.org/docs/source-date-epoch/
+ifdef SOURCE_DATE_EPOCH
+  BUILD_DATE          := $(shell $(DATE) +%F --utc --date="@$(SOURCE_DATE_EPOCH)")
+else
+  BUILD_DATE          := $(shell $(DATE) +%F)
+endif
+
 ##############################################################################
 # This makefile uses the $(eval) builtin function, which was added in
 # GNU make 3.80.  Check that the current make version recognizes it.