bug#56338: ‘guix refresh -u’ stops at the first failure to determine releases

[Ludovic Courtès]

Starting from commit 53b9c27aa59bebf955f0aa24fef60a101480ef5c (a fix for
<https://issues.guix.gnu.org/55987>), we get:

--8<---------------cut here---------------start------------->8---
$ ./pre-inst-env guix refresh -t cran r-a3 r-googlesheets r-a4 -u
gnu/packages/bioconductor.scm:9233:2: warning: no updater for r-a4
guix refresh: warning: failed to retrieve package information from 
https://cran.r-project.org/web/packages/googlesheets/DESCRIPTION: 404 (Not 
Found)
guix refresh: error: updater failed to determine available releases for 
r-googlesheets
--8<---------------cut here---------------end--------------->8---

That is, ‘guix refresh -u’ stops on the first failure (in this case
‘r-a3’ is not processed).  That makes it hard to use for mass updates as
in ‘guix refresh -t cran -u’.

(Reported by Ricardo on #guix.)

Ludo’.