04/12: maint: Help help2man generate reproducible man-pages.

[guix-commits]

janneke pushed a commit to branch wip-tarball
in repository guix.

commit 34915f43ed2e8b7ae99c3fe2fd65e7b97ff8f57b
Author: Janneke Nieuwenhuizen <janneke@gnu.org>
AuthorDate: Sat Sep 9 13:35:40 2023 +0200

    maint: Help help2man generate reproducible man-pages.
    
    * doc/local.mk (SOURCE_DATE_EPOCH): New exported variable.
    
    Change-Id: I6636693695d5502657f1475d93d31949e0b0b39d
---
 doc/local.mk | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/doc/local.mk b/doc/local.mk
index 5f014b9c3d..017686137a 100644
--- a/doc/local.mk
+++ b/doc/local.mk
@@ -224,6 +224,9 @@ gen_man =                                           \
   $(HELP2MANFLAGS)
 
 HELP2MANFLAGS = --source=GNU --info-page=$(PACKAGE_TARNAME)
+# help2man reproducibility
+SOURCE_DATE_EPOCH = $(shell git show HEAD --format=%ct --no-patch 2>/dev/null 
|| echo 0)
+export SOURCE_DATE_EPOCH
 
 $(srcdir)/%D%/guix.1: scripts/guix.in $(sub_commands_mans)
        -$(AM_V_HELP2MAN)$(gen_man) --output="$@" `basename "$@" .1`