Re: Persistent failure to lookup hostname

[Stefan Monnier]

>> 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)?

That's a good question, I should check that as well next time,
indeed, thanks.

[ Not sure why it didn't occur to me back then.  Apparently I was
  looking for ways to get my IMAP connection working more than for ways
  to diagnose the problem.  ]

>> > 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/

I did check for `nscd` and I know it's not running `dnsmasq` any more no
that machine (I know because I used to run it), but I haven't checked
`systemd-resolved` yet.

Thanks.


        Stefan