From <https://github.com/bmwiedemann/psm/commit/98acae1a6f2c9b2e6014eac4070a817c9d0fd8a2>.

From 98acae1a6f2c9b2e6014eac4070a817c9d0fd8a2 Mon Sep 17 00:00:00 2001
From: "Bernhard M. Wiedemann" <bwiedemann@suse.de>
Date: Sun, 23 Jul 2017 07:02:28 +0200
Subject: [PATCH] Allow to override build date

in order to make builds reproducible.
See https://reproducible-builds.org/ for why this is good
and https://reproducible-builds.org/specs/source-date-epoch/
for the definition of this variable.

Also uses UTC to be independent of timezone settings.
---
 Makefile       | 2 +-
 ipath/Makefile | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index d79c4bd..99406ef 100644
--- a/Makefile
+++ b/Makefile
@@ -270,7 +270,7 @@ ${TARGLIB}.so.${MAJOR}: ${TARGLIB}.so.${MAJOR}.${MINOR}
 # file around.  Generate it such that the ident command can find it
 # and strings -a | grep InfiniPath does a reasonable job as well.
 ${TARGLIB}.so.${MAJOR}.${MINOR}: ${${TARGLIB}-objs}
-	date +'char psmi_infinipath_revision[] ="$$""Date: %F %R ${rpm_extra_description}InfiniPath $$";' > ${lib_build_dir}/_revision.c
+	date -u -d@$${SOURCE_DATE_EPOCH:-$$(date +%s)} +'char psmi_infinipath_revision[] ="$$""Date: %F %R ${rpm_extra_description}InfiniPath $$";' > ${lib_build_dir}/_revision.c
 	$(CC) -c $(BASECFLAGS) $(INCLUDES) _revision.c -o _revision.o
 	$(CC) $(LDFLAGS) -o $@ -Wl,-soname=${TARGLIB}.so.${MAJOR} -shared -Wl,--unique='*fastpath*' \
 		${${TARGLIB}-objs} _revision.o -L$(build_dir)/ipath $(LDLIBS)
diff --git a/ipath/Makefile b/ipath/Makefile
index 8c2cc6e..73abd6f 100644
--- a/ipath/Makefile
+++ b/ipath/Makefile
@@ -70,7 +70,7 @@ ${TARGLIB}.so.${MAJOR}: ${TARGLIB}.so.${MAJOR}.${MINOR}
 # file around.  Generate it such that the ident command can find it
 # and strings -a | grep InfiniPath does a reasonable job as well.
 ${TARGLIB}.so.${MAJOR}.${MINOR}: ${${TARGLIB}-objs}
-	date +'static __attribute__ ((unused)) char __psc_infinipath_revision[] ="$$""Date: %F %R ${rpm_extra_description}InfiniPath $$";' > _revision.c
+	date -u -d@$${SOURCE_DATE_EPOCH:-$$(date +%s)} +'static __attribute__ ((unused)) char __psc_infinipath_revision[] ="$$""Date: %F %R ${rpm_extra_description}InfiniPath $$";' > _revision.c
 	$(CC) -c $(BASECFLAGS) $(INCLUDES) _revision.c -o _revision.o
 	$(CC) -o $@ -Wl,-soname=${TARGLIB}.so.${MAJOR} -shared \
 		-Wl,--unique='*fastpath*' \
585f1dcf417'>Collapse</a>)</th><th class='left'>Author</th></tr>
<tr class='logheader'><td><span title='2023-09-09 18:47:35 +0200'>2023-09-09</span></td><td class='logsubject'><a href='/guix/commit/nix?id=cd469932758bf2bec1ff9c82aeb373e18730d0c4'>daemon: Fix build with GCC 13.</a></td><td>Sören Tempel</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
The sqlite.hh file uses fixed-width integer types from stdint.h. As
such, it needs to include &lt;cstdint&gt;. Without this include, the file
doesn't compile successfully with GCC13.

See: https://gcc.gnu.org/gcc-13/porting_to.html#header-dep-changes

* nix/libstore/sqlite.hh: include &lt;cstdint&gt;

Signed-off-by: Sören Tempel &lt;soeren@soeren-tempel.net&gt;
Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;


</td></tr>
<tr class='logheader'><td><span title='2023-08-31 23:31:49 -0400'>2023-08-31</span></td><td class='logsubject'><a href='/guix/commit/nix?id=69f6edc1a8596d2cb4c67e0435d35633af6f3cbc'>build: Add missing guix-gc.timer file to binary tarball.</a></td><td>Maxim Cournoyer</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
Partially fixes &lt;https://issues.guix.gnu.org/65117&gt;.

* nix/local.mk (nodist_systemdservice_DATA): Add etc/guix-gc.timer.


</td></tr>