Re: Persistent failure to lookup hostname

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: emacs-devel@gnu.org
> Date: Tue, 04 Oct 2022 09:24:36 -0400
> 
> Eli Zaretskii [2022-10-04 09:51:44] wrote:
> >> Does anyone here have an idea why `getaddrinfo` might return an outdated
> >> error, or whether it could come from elsewhere?  Or how/where I might
> >> find a kind of DNS cache that would be process-local rather
> >> than systemwide?
> > Is it certain that the problem is specific to that single process?
> 
> No.  But it's certain that it's not system-wide because all the other
> processes (including a fresh new Emacs session, and an older Emacs
> session that rarely/never uses network connections) I tried had no
> problem resolving that same address.

You are saying that the affected Emacs session cannot use eww or any
of the url code to access sites (or just that IMAP site)?

> > Did you try flushing and renewing the system's DNS cache with the
> > appropriate shell commands?
> 
> I don't know that I have such a thing on this system.

Could be.  Maybe the next links will help:

  https://devconnected.com/how-to-flush-dns-cache-on-linux/
  https://beebom.com/how-flush-dns-cache-linux/
  https://linuxize.com/post/how-to-clear-the-dns-cache/