From mboxrd@z Thu Jan  1 00:00:00 1970
From: Federico Beffa <beffa@ieee.org>
Subject: Re: reproducibility
Date: Tue, 12 Jan 2016 21:11:47 +0100
Message-ID: <CAKrPhPMn_gQMyRoa8b8ZV=o8rovfUPTbVNQnR=PraLWgXuYq3Q@mail.gmail.com>
References: <CAKrPhPP+j6jfmLFk5WuHxa6q=fRO++KHkeOZ4kC-Mnw8ZxNcSA@mail.gmail.com>
	<874mel2m94.fsf@gnu.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Return-path: <guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:35240)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <federico.beffa@gmail.com>) id 1aJ5ID-0003vE-LW
	for guix-devel@gnu.org; Tue, 12 Jan 2016 15:11:50 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <federico.beffa@gmail.com>) id 1aJ5IC-0006WZ-ML
	for guix-devel@gnu.org; Tue, 12 Jan 2016 15:11:49 -0500
In-Reply-To: <874mel2m94.fsf@gnu.org>
List-Id: "Development of GNU Guix and the GNU System distribution."
	<guix-devel.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/guix-devel>,
	<mailto:guix-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/guix-devel>
List-Post: <mailto:guix-devel@gnu.org>
List-Help: <mailto:guix-devel-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/guix-devel>,
	<mailto:guix-devel-request@gnu.org?subject=subscribe>
Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org
Sender: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org
To: =?UTF-8?Q?Ludovic_Court=C3=A8s?= <ludo@gnu.org>
Cc: Guix-devel <guix-devel@gnu.org>

On Sun, Jan 10, 2016 at 9:49 PM, Ludovic Court=C3=A8s <ludo@gnu.org> wrote:
> Federico Beffa <beffa@ieee.org> skribis:
>
>> I've noticed that a derivation is a function of the order of the
>> inputs. As an example, the following two input orders give rise to two
>> distinct derivations:
>>
>> A)
>>
>>     (inputs
>>      `(("texlive" ,texlive)
>>        ("texinfo" ,texinfo)
>>        ("m4" ,m4)
>>        ("libx11" ,libx11))
>>
>> B)
>>     (inputs
>>      `(("texinfo" ,texinfo)
>>        ("texlive" ,texlive)
>>        ("m4" ,m4)
>>        ("libx11" ,libx11))
>>
>> Is this intentional?
>
> Yes.  There are several places where order matters, most importantly
> search paths, and these are computed from the input lists.

If order matters, it would probably be more robust to force internally
a specific order rather than relying on the (often random) order
defined in a package recipe (possibly created by an importer, ...).

Fede