bug#75065: Upon archive download failure print the original error

[Konstantin Kharlamov <Hi-Angel@yandex.ru>]

Oh, actually, let me fix the other place as well then…

On Thu, 2024-12-26 at 23:51 +0300, Konstantin Kharlamov wrote:
> On Thu, 2024-12-26 at 15:40 -0500, Stefan Monnier wrote:
> > > The `car` seems to just contain word error. Here's how both
> > > compare:
> > > 
> > > • current patch with `(cdr err)`:
> > >     Failed to download ‘melpa’ archive. Error: ("Location
> > > melpa.org/packages/ is not a url nor an absolute file name")
> > > 
> > > • suggested change with `err`:
> > >     Failed to download ‘melpa’ archive. Error: (error "Location
> > > melpa.org/packages/ is not a url nor an absolute file name")
> > > 
> > > I can of course remove the word `Error` in the second case.
> > > My question then is: will `(car err)` always be the word "error"?
> > > Or
> > > may there be another content?
> > 
> > The shape and content of `err` depends on the actual error that
> > caused
> > the download to fail.  `(car err)` contains the error "type", which
> > can
> > be `error` but can also be more specific such as
> > `wrong-number-of-arguments`, `file-error`, ...
> 
> Thank you, I see!
> 
> Please check the attached patch. With this change the error of
> accessing https-less address is shown as follows:
> 
> 	Failed to download ‘melpa’ archive: (error "Location
> melpa.org/packages/ is not a url nor an absolute file name")