nixpkgs/pkgs/development/tools/misc/automake/help2man-SOURCE_DATE_EPOCH-support.patch
David Terry cd87f1ba23 automake-1.15: deterministic documentation generation
automake 1.15 uses a bundled version of help2man from 2012 that
does not support the SOURCE_DATE_EPOCH environment variable.

This means that the build date is included in the generated
documentation, breaking reproducibility.

This changes adds the SOURCE_DATE_EPOCH support from the current
help2man to the version bundled in automake 1.15.
2019-11-03 10:55:45 +01:00

42 lines
1.6 KiB
Diff

From 2e3357d7f0d63f1caeb40d9644c2436a5cd0da5f Mon Sep 17 00:00:00 2001
From: David Terry <me@xwvvvvwx.com>
Date: Fri, 18 Oct 2019 10:23:11 +0200
Subject: [PATCH] help2man: add support for SOURCE_DATE_EPOCH
---
doc/help2man | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/doc/help2man b/doc/help2man
index af4306f..4a64167 100755
--- a/doc/help2man
+++ b/doc/help2man
@@ -213,11 +213,23 @@ sub get_option_value;
my $help_text = get_option_value $ARGV[0], $help_option;
$version_text ||= get_option_value $ARGV[0], $version_option;
+# By default the generated manual pages will include the current date. This may
+# however be overriden by setting the environment variable $SOURCE_DATE_EPOCH
+# to an integer value of the seconds since the UNIX epoch. This is primarily
+# intended to support reproducible builds (wiki.debian.org/ReproducibleBuilds)
+# and will additionally ensure that the output date string is UTC.
+my $epoch_secs = time;
+if (exists $ENV{SOURCE_DATE_EPOCH} and $ENV{SOURCE_DATE_EPOCH} =~ /^(\d+)$/)
+{
+ $epoch_secs = $1;
+ $ENV{TZ} = 'UTC';
+}
+
# Translators: the following message is a strftime(3) format string, which in
# the English version expands to the month as a word and the full year. It
# is used on the footer of the generated manual pages. If in doubt, you may
# just use %x as the value (which should be the full locale-specific date).
-my $date = enc strftime _("%B %Y"), localtime;
+my $date = enc strftime _("%B %Y"), localtime $epoch_secs;
(my $program = $ARGV[0]) =~ s!.*/!!;
my $package = $program;
my $version;
--
2.23.0