From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark H Weaver <mhw@netris.org>
Subject: bug#26734: Snippets (even empty ones) of tar sources reset the
	timestamps of all files
Date: Wed, 03 May 2017 17:45:20 -0400
Message-ID: <87r305iphr.fsf@netris.org>
References: <874lx4d6j7.fsf@lassieur.org> <87h913h0rj.fsf@gnu.org>
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In-Reply-To: <87fugmxqng.fsf@gnu.org> ("Ludovic
	\=\?utf-8\?Q\?Court\=C3\=A8s\=22'\?\=
	\=\?utf-8\?Q\?s\?\= message of "Wed, 03 May 2017 10:58:59 +0200")
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To: Ludovic =?UTF-8?Q?Court=C3=A8s?= <ludo@gnu.org>
Cc: 26734@debbugs.gnu.org, =?UTF-8?Q?Cl=C3=A9ment?= Lassieur <clement@lassieur.org>

ludo@gnu.org (Ludovic Court=C3=A8s) writes:

> BTW, what timestamps to we put on the modified files?  We want that to
> be deterministic so we cannot use the build time.  We cannot use a date
> in the future, either.  We cannot use Jan. 1 1970 either because that
> means that modified files may now be older than the unmodified files,
> which may break build systems; for the same reason, we cannot leave the
> mtime of modified files unchanged.
>
> Now that I think about it, it=E2=80=99s not clear to me what can be done =
without
> breaking something.
>
> Thoughts?

We could set the timestamp of modified files to be 1 second newer than
the newest file in the original source archive.

      Mark