bug#50597: different fixed-output when using ’--with-source’ transformation

[zimoun]

Hi Ludo,

On Sat, 18 Sep 2021 at 18:06, Ludovic Courtès <ludo@gnu.org> wrote:
> zimoun <zimon.toutoune@gmail.com> skribis:
>
>> Why the store item of source tarball is it different when applying the
>> transformation?
>>
>> Maxime provided a clue [1].
>
> Maxime is right: ‘--with-source’ passes #:recursive? #t unconditionally,
> whereas it’s usually #f for a ‘url-fetch’ kind of URI.

Thanks for confirming.  Why is it different?


> What we could do is make it #t if and only if the URL denotes a local
> file and that file is a directory.  I think that would achieve what you
> want without any observable regression in practice.

What I expect is that 2 (fixed-output) files with the same hash
(0ssi1w…) lives at the same store location…

--8<---------------cut here---------------start------------->8---
$ guix hash /gnu/store/chariqd6k0sli3s7vcl4q3al0crirz5v-hello-2.10.tar.gz
0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i

$ guix hash /gnu/store/hbdalsf5lpf01x4dcknwx6xbn6n5km6k-hello-2.10.tar.gz
0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i
--8<---------------cut here---------------end--------------->8---

…whatever if these (fixed-output) files come from “guix download”, “guix
build -S” or “--with-source=https://” or etc.

The mapping from hash (0ssi1w…) to store location should be 1:1 for
fixed-output, IMHO.

Cheers,
simon