bug#63024: Crash during `guix import pypi -r'

[Timo Wilken]

The `guix import pypi -r ...' command frequently crashes for me. When
it does, it always crashes on the third download, the one for the
first dependency's source distribution, like so:

--8<---------------cut here---------------start------------->8---
$ guix import pypi -r calcure

Starting download of /tmp/guix-file.7aaMby
>From 
>https://files.pythonhosted.org/packages/61/e3/c960430852d4322d42e02421690958f47fa2b42aaf4f3befb25c1c8baf21/calcure-2.8.6.tar.gz...
 …8.6.tar.gz  42KiB          2.1MiB/s 00:00 [##################] 100.0%

Starting download of /tmp/guix-file.mPnbsd
>From 
>https://files.pythonhosted.org/packages/b5/a8/8ba240c952a13b3b2bee64356dc1a1515c496100dc4c9edb6a6648927864/calcure-2.8.6-py3-none-any.whl...
 …y3-none-any.whl  49KiB     1.9MiB/s 00:00 [##################] 100.0%

Starting download of /tmp/guix-file.XzIPz0
>From 
>https://files.pythonhosted.org/packages/24/91/77edc7626400922d44019753c39e0fd911176ce3f77c3f85ac832d5d70b7/holidays-0.23.tar.gz...
In procedure connect*: Connection timed out

Starting download of /tmp/guix-file.XzIPz0
>From 
>https://web.archive.org/web/20230422212928/https://files.pythonhosted.org/packages/24/91/77edc7626400922d44019753c39e0fd911176ce3f77c3f85ac832d5d70b7/holidays-0.23.tar.gz...
In procedure connect*: Connection timed out
Trying to use Disarchive to assemble /tmp/guix-file.XzIPz0...
could not find its Disarchive specification
failed to download "/tmp/guix-file.XzIPz0" from 
"https://files.pythonhosted.org/packages/24/91/77edc7626400922d44019753c39e0fd911176ce3f77c3f85ac832d5d70b7/holidays-0.23.tar.gz";
Backtrace:
          10 (primitive-load "/home/timo/.config/guix/current/bin/gu…")
In guix/ui.scm:
   2300:7  9 (run-guix . _)
  2263:10  8 (run-guix-command _ . _)
In guix/scripts/import.scm:
    89:11  7 (guix-import . _)
In ice-9/boot-9.scm:
  1752:10  6 (with-exception-handler _ _ #:unwind? _ # _)
In guix/scripts/import/pypi.scm:
    97:21  5 (_)
In guix/import/utils.scm:
    638:3  4 (recursive-import _ #:repo->guix-package _ #:guix-name . #)
   600:31  3 (topological-sort _ #<procedure 7f668bf7a8d0 at guix/i…> …)
In srfi/srfi-1.scm:
   586:17  2 (map1 (("holidays" #f) ("jdatetime" #f) ("ics" #f)))
In guix/import/utils.scm:
   630:33  1 (lookup-node "holidays" #f)
In ice-9/boot-9.scm:
  1685:16  0 (raise-exception _ #:continuable? _)

ice-9/boot-9.scm:1685:16: In procedure raise-exception:
Wrong number of values returned to continuation (expected 2)
--8<---------------cut here---------------end--------------->8---

However, that URL is valid -- running a manual `guix download'
afterwards works fine:

--8<---------------cut here---------------start------------->8---
$ guix download 
'https://files.pythonhosted.org/packages/24/91/77edc7626400922d44019753c39e0fd911176ce3f77c3f85ac832d5d70b7/holidays-0.23.tar.gz'
  

Starting download of /tmp/guix-file.vsuTGB
>From 
>https://files.pythonhosted.org/packages/24/91/77edc7626400922d44019753c39e0fd911176ce3f77c3f85ac832d5d70b7/holidays-0.23.tar.gz...
 ….23.tar.gz  374KiB     2.5MiB/s 00:00 [##################] 100.0%
/gnu/store/jk0v685hhwirl16la349c7i5is640181-holidays-0.23.tar.gz
0yxs1lzbqykl25yf1hcrqjb7qqw69f2zgf7991slnkmk98p1bsxw
--8<---------------cut here---------------end--------------->8---