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From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: Proposal: prefetch tarballs in a batch
Date: Thu, 03 Apr 2014 09:24:35 +0200
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To: Nikita Karetnikov <nikita@karetnikov.org>
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Nikita Karetnikov <nikita@karetnikov.org> skribis:

>>> Is there a function that accepts a package name and returns a list of
>>> implicit inputs?
>
>> No, because by definition, those =E2=80=9Cimplicit inputs=E2=80=9D are n=
ot listed in the
>> package object.  Instead, they are added by the build system (see
>> build-system/gnu.scm.)
>
>> That=E2=80=99s why I suggested using derivations instead: take the outpu=
t of
>> (package-derivation x y), and traverse it in search of fixed-output
>> derivations.
>
> What=E2=80=99s a fixed-ouput derivation?

A derivation whose result (hash thereof) is known in advance, as is the
case for downloads (info "(guix) Derivations").

Ludo=E2=80=99.