+# Reproducible builds, accept a build timestamp override from environ per
+# <https://reproducible-builds.org/specs/source-date-epoch/>.
+# We require a fairly modern date(1) command here, which is not portable
+# to some of the systems Exim is built on. That's okay, because the scenarios
+# are:
+# 1) Local postmaster building, not using $SOURCE_DATE_EPOCH, doesn't matter
+# 2) Packaging folks who don't care about reproducible builds
+# 3) Packaging folks who care but are using systems where date Just Works
+# 3) Packaging folks who care and can put a modern date(1) in $PATH
+# 4) Packaging folks who care and can supply us with a clean patch to support
+# their requirements
+# 5) Packaging folks who care but won't do any work to support their strange
+# old systems and want us to do the work for them. We don't care either,
+# they're SOL and have to live without reproducible builds.
+#
+exim_build_date_override=''
+if [ ".${SOURCE_DATE_EPOCH:-}" != "." ]; then
+ fmt='+%d-%b-%Y %H:%M:%S'
+ # Non-reproducible, we use __DATE__ and __TIME__ in C, which respect timezone
+ # (think localtime, not gmtime); for reproduction between systems, UTC makes
+ # more sense and the examples available use UTC without explicitly mandating
+ # it. I think that we can switch behavior and use UTC for reproducible
+ # builds without it causing any problems: nothing really cares about timezone.
+ # GNU date: "date -d @TS"
+ # BSD date: "date -r TS"
+ exim_build_date_override="$(date -u -d "@${SOURCE_DATE_EPOCH}" "$fmt" 2>/dev/null || date -u -r "${SOURCE_DATE_EPOCH}" "$fmt" 2>/dev/null)"
+fi
+
git://git.exim.org / users / heiko / exim.git / blobdiff