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 23:36:36 -0500
> Cc: mirko.vukovic@gmail.com, 42984@debbugs.gnu.org
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> 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.
> 
> Should we do anything about that, or is it expected?

My guess is it's not an Emacs problem.  But to be sure, I miss some
details:

  . is gpg being used an MSYS2 port of a native Windows
    (a.k.a. "mingw") port?
  . was the problematic file name emitted by gpg, or was it generated
    by Emacs and passed to gpg?

The last question could be answered by stepping in Edebug through
package--check-signature-content and epg functions it calls, and
looking at the file names we place on the gpg command line.

If the OP could provide this information, we could easily see whether
there's some problem in Emacs in this use case.