On Tue, 3 Jul 2018 15:49:06 +0200
Stefan Krusche <linux@...> wrote:

> Good day everyone,
> 
> I'm using trinity 14.0.5 from preliminary stable builds on devuan ascii
> (debian stretch).
> 
> Through the most recent upgrade, that I executed on 2018-07-02 11:42:01,
> tdm (amongst a couple others) got upgraded:
> 
> tdm-trinity:amd64 (4:14.0.5~pre39-0debian9.0.0+6, 4:14.0.5~pre42-0debi
> an9.0.0+6)
> 
> After this upgrade tdm wouldn't start anymore and in /var/log/boot I
> found this error message:
> 
> Not starting Trinity Display Manager (tdm); it is not the default display 
> manager.
> 
> The file is there:
> $ ls -l /etc/X11/default-display-manager
> -rw-r--r-- 1 root root 14 Jul  2 11:42 /etc/X11/default-display-manager
> 
> And it says:
> $ cat /etc/X11/default-display-manager
> /usr/bin/slim
> 
> Solution:
> 
> $ dpkg-reconfigure tdm-trinity
> 
> Of course, tdm was the default display manager already before the
> upgrade, and, as you can guess from the above, slim is installed, too.
> 
> I think, it should not be necessary to reconfigure the display manager,
> or, least, the user should be prompted to do so at installation.
> 
> IIRC, this happened already at the previous upgrade to ~pre39.
> 
> Has anybody seen this? Do you think it is a bug?
> 

First, a you sure that slim wasnt updated too? Because if it was it is most
likely bug in slim. If not than this looks like a problem with debconf
database (or a bug in debconf).
Look in /var/cache/debconf/config.dat for shared/default-x-display-manager
and post a context of this section



-- 
  Nick Koretsky (nick.koretsky@...)