bug#28596: 26.0.60; [Gnus] Checking mail is no longer reliable and C-g no longer quits

[Eli Zaretskii <eliz@gnu.org>]

> From: nljlistbox2@gmail.com (N. Jackson)
> Date: Mon, 25 Sep 2017 11:01:01 -0400
> 
> Yesterday I switched from Emacs 25 to the emacs-26 branch. With
> this Gnus hangs (sometimes) when checking mail/news
> (`gnus-group-get-new-news') and then C-g no longer quits -- at
> least not immediately.
> 
> The hangs are for long enough for Gnome dialogs to appear saying
> that Emacs is no longer responding. Eventually control comes back
> to Emacs but that might be due to repeated presses of C-g.

This could be due to the fact that Emacs 26 uses async communications
more than previous versions.

Does gnus-group-get-new-news use any of the url-* functions?  If so,
perhaps try setting url-asynchronous to nil when fetching news, to see
if that solves the problem.  Or maybe even build Emacs with
HAVE_GETADDRINFO_A undefined, and see if that helps.

(I'm not saying that these should be the solutions for this bug, just
that they might tell us whether the asynchronous communications
features are involved here.)

I think it would also help stepping through the failing functions with
a debugger and seeing which parts of them fail.

Thanks.