bug#42984: 27.1; package-list results in error while updating archive due to malformed path

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Wed, 25 Nov 2020 16:06:43 -0500
> Cc: 42984@debbugs.gnu.org
> 
> > package-gnupghome-dir ==> "c:/Users/977315/.emacs.d/elpa/gnupg"
> > package-user-dir: ==> "~/.emacs.d/elpa"
> > (expand-file-name "gnupg" package-user-dir) ==>
> > "c:/Users/977315/.emacs.d/elpa/gnupg"
> 
> Well, I'm stomped.  But I don't know much of anything about Windows.
> 
> Does anyone have an idea why a path like this would be used on Windows?
> 
>   "/c/Users/977315/tmp/c:/Users/977315/.emacs.d/elpa/gnupg/pubring.kbx"

Yes, it happens when MSYS2 ports of programs (gpg?) are mixed with
native Windows ports.