bug#46191: Add option to make "guix refresh" keep the downloaded files

[Ludovic Courtès]

Hi Hartmut,

Hartmut Goebel <h.goebel@crazy-compilers.com> skribis:

> When running "guix refresh -u some-package" downloads the package to
> update the hash. But the source is not added to the store, Thus when 
> running "guix build some-package", the source will be downloaded again.

Unless I’m missing something, the source *is* added to the store; see
the ‘download-to-store’ call in (guix upstream).

Could you double-check?

Thanks,
Ludo’.