build: export SOURCE_DATE_EPOCH

SOURCE_DATE_EPOCH is used to set various timestamps in build
products, and was introduced as part of the reproducible
builds efforts.

this is a great help for future build system restructuring,
as the "diffoscope"-diff of the produced .debs is now small
enough to catch unintended changes.

diff --git a/Makefile b/Makefile
index a2ca354193c2002d2da7d9b3928eedd89521a2d9..2deadfa670e23391ff6a930d39db2c61da7a53e8 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -18,6 +18,7 @@ HDRPACKAGE=pve-headers-${KVNAME}
 ARCH=amd64
 GITVERSION:=$(shell cat .git/refs/heads/master)
 CHANGELOG_DATE:=$(shell dpkg-parsechangelog -SDate -lchangelog.Debian)
+export SOURCE_DATE_EPOCH ?= $(shell dpkg-parsechangelog -STimestamp -lchangelog.Debian)
 
 SKIPABI=0