Subject: Re: [bug#58017] [PATCH 2/2] substitute: Retry downloading when a nar is unavailable.

From: Ludovic Courtès <[email-masked]>
Date: Sat, 24 Sep 2022 18:22:59 +0200

Hi Maxime,

Maxime Devos <[email-masked]> skribis:

>> +(test-equal "substitute, first URL has narinfo but nar is 404, both URLs authorized"
>> +  "Substitutable data."
>> +  (with-narinfo*
>> +      (string-append %narinfo "Signature: "
>> +                     (signature-field %narinfo))
>> +      %main-substitute-directory
>> +
>> +    (with-http-server `((200 ,(string-append %narinfo "Signature: "
>> +                                             (signature-field %narinfo)))
>> +                        (404 "Sorry, nar is missing!"))
>> +      (dynamic-wind
>> +        (const #t)
>> +        (lambda ()
>> +          (parameterize ((substitute-urls
>> +                          (list (%local-url)
>> +                                (string-append "file://"
>> +                                               %main-substitute-directory))))
>> +            (request-substitution (string-append (%store-prefix)
>> +                                                 "/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-foo")
>> +                                  "substitute-retrieved"))
>> +          (call-with-input-file "substitute-retrieved" get-string-all))
>> +        (lambda ()
>> +          (false-if-exception (delete-file "substitute-retrieved")))))))
>
> Shouldn't it only ignore 'file not found' (ENOENT?) exceptions?

By “it”, do you mean ‘dynamic-wind’ should be replaced by a ‘catch’
form?

We could discuss it, but note that this patch just keeps with the style
of existing tests.

> This test, and some others, can be improved by also checking the
> URI. While currently 'with-http-server' does not support that, there
> are (5 months, with the v1 having seen some reviewing and a v2
> available) patches for that at <https://issues.guix.gnu.org/53389>.
>
> That patch also _requires_ always mentioning the URI, if the cover
> letter is correct.  It also allows simplifying the use of '%local-url'
> a bit.

Ah, thanks for the reminder!  I’ve just spent most of the day reviewing
patches, but not that one…

Ludo’.