[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: reproducibility
From: |
Ludovic Courtès |
Subject: |
Re: reproducibility |
Date: |
Wed, 13 Jan 2016 14:56:38 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) |
Federico Beffa <address@hidden> skribis:
> On Tue, Jan 12, 2016 at 10:37 PM, Ludovic Courtès <address@hidden> wrote:
>> Federico Beffa <address@hidden> skribis:
>>
>>> On Sun, Jan 10, 2016 at 9:49 PM, Ludovic Courtès <address@hidden> wrote:
>>>> Federico Beffa <address@hidden> 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, ...).
>>
>> Most of the time any order would work, but I can imagine situations
>> where the packager could purposefully choose a specific order. So I’d
>> rather not do any automatic sorting, if that’s what you have in mind.
>
> Just out of curiosity, could you provide a concrete example where the
> order is purposefully specified.
No specific example, sorry, but it’s plausible IMO. With enough CPU
power, we could try rebuilding everything with a random order and see
what breaks.
Thanks,
Ludo’.