From: Felix Fietkau <nbd@openwrt.org>
Date: Thu, 18 Jun 2015 06:41:45 +0000 (+0000)
Subject: ipkg-build: suppress timestamps in gzip headers
X-Git-Tag: reboot~2747
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=949d7e30e418ad2197f2ffe14e701b56b9d9ea4e;p=openwrt%2Fstaging%2Fxback.git

ipkg-build: suppress timestamps in gzip headers

When creating control.tar.gz, data.tar.gz and $package.ipk
tar compresses them with default gzip options.
This includes build timestamps in their gzip headers.
By setting the GZIP env variable to -n, gzip no longer embeds
them, which is a step towards reproducibility.

See also [1] for more detailed motivations.

[1]: https://wiki.debian.org/ReproducibleBuilds/About

Signed-off-by: Reiner Herrmann <reiner@reiner-h.de>

SVN-Revision: 46026
---

diff --git a/scripts/ipkg-build b/scripts/ipkg-build
index c466f28681..6787ed4199 100755
--- a/scripts/ipkg-build
+++ b/scripts/ipkg-build
@@ -13,6 +13,7 @@ version=1.0
 FIND="$(which find)"
 FIND="${FIND:-$(which gfind)}"
 TAR="${TAR:-$(which tar)}"
+export GZIP="-n"
 
 ipkg_extract_value() {
 	sed -e "s/^[^:]*:[[:space:]]*//"