Re: reproducibility

[Federico Beffa <beffa@ieee.org>]

On Sun, Jan 10, 2016 at 9:49 PM, Ludovic Courtès <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