Bug#1125682: xterm sessions do not appear in loginctl output

On 2026-02-04 19:58:56 -0500, Thomas Dickey wrote:
> On Wed, Feb 04, 2026 at 02:13:09PM +0100, Vincent Lefevre wrote:
> > On 2026-02-04 12:40:00 +0100, Chris Hofstaedtler wrote:
> > > This is your assessment of things. It is still unknown if xterm 
> > > needs any changes or not. I'll defer to the xterm author for this.
> > 
> > If xterm does not need any change, then what is the cause of the
> > issue?
> 
> Basically, removing utmp breaks any user of libtempter.
> (apt-cache says there are a few others than xterm).

Yes, when utmp was removed from Debian, various things using it
suddenly broke (not just libtempter). Some of them got fixed in
some way.

> So... I'll have to investigate and see if the advice in #1072235 was useful.
> 
> (utmp and wtmp have different purposes, and if it was only aimed at wtmp,
> the advice was not useful).

Agreed.

Writing to wtmpdb (which is debatable for xterm sessions) would not
solve the issue with "wall". I can see this when connecting with ssh:
an entry is written to wtmpdb (mentioning "still logged in" and with
an associated tty there), but "wall" (run as root to ensure that it
has sufficient permissions) does not output anything in the terminal.
So wtmpdb is not used by "wall".

Note that Chris Hofstaedtler said in

  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1115259#10

"Make sure your sessions are listed in `loginctl` output (with a TTY)."

In the case of ssh, the session is listed in loginctl output, but
*without* a TTY. That's the following bug (reported by Chris):

  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1087644