calculated BUILD_DATE based on SOURCE_DATE_EPOCH

rather than parsing d/changelog

diff --git a/debian/rules b/debian/rules
index 612807e5dba395fc132dbfd48dcf4c4cd126db0e..fc54a56bd0b5ea42dc3ebb27c6eddd2a9cafcf68 100755 (executable)
--- a/debian/rules
+++ b/debian/rules
@@ -1,12 +1,17 @@
 #!/usr/bin/make -f
 
-DATE := $(shell date -u -d "$$(dpkg-parsechangelog -SDate)" +"%Y/%m/%d")
-
 export DEB_BUILD_MAINT_OPTIONS = hardening=+all
 
 export DEB_LDFLAGS_MAINT_APPEND = -Wl,--as-needed
 
-CPPFLAGS+=-DBUILD_DATE='"$(DATE)"'
+DATE_FMT = %Y-%m-%d
+ifdef SOURCE_DATE_EPOCH
+    BUILD_DATE ?= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "+$(DATE_FMT)"  2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "+$(DATE_FMT)" 2>/dev/null || date -u "+$(DATE_FMT)")
+else
+    BUILD_DATE ?= $(shell date "+$(DATE_FMT)")
+endif
+
+CPPFLAGS+=-DBUILD_DATE='"$(BUILD_DATE)"'
 CXXFLAGS+=-std=c++11
 
 %: