Re: debian sid no boot after this morning's update
On 1/5/23 09:53, Greg Wooledge wrote:
/snip/
Error writing X authority: Failed to open X authority
/var/lib/lightdm/.Xauthority: Permission denied
Does that file exist? If so, ls -ld /var/lib/lightdm/.Xauthority
If not, ls -ld /var/lib/lightdm
Hell, just do both regardless of whether the file currently exists.
It's one command with two lines of output. Should be the first thing
you do.
Yes, the file exists and is owned by lightdm. I don't know whether this is
correct as I can't find any info on who should own it.
I tried moving it out of the way hoping lightdm or the greeter would
recreate but no luck.
Hmm, that's weird indeed. If the file is owned by lightdm (the user),
that implies that lightdm (the program) was able to write it in the past.
If it can't do so now, then we have to try to guess what changed which
could lead to this result.
Possibility 1: lightdm (the program) no longer runs as lightdm (the user).
Pissibility 2: a new restriction has been added to the service which
launches lightdm (the program). Something at the AppArmor level, or at
the systemd unit level, perhaps.
It is strange as there were no updates yesterday of lightdm or the greeter.
How about in recent days? Maybe a change occurred a few days ago, but
you hadn't rebooted, so the changes didn't actually have any impact yet.
The GTK
greeter was updated the day before but Debian started and ran fine after
that.
I don't know what this is. A separate package?
Lightdm uses various greeters which provide various login appearances to
the user.
This is confusing. Are you saying that you have a multi-boot system,
with both Debian and Fedora installed on the same hard drive? And that
you booted into Fedora, then mounted the Debian root file system somewhere,
and then chrooted into it?
Yes I have a multi boot system. I only mounted Debian in Fedora to read
log files, and move the two deb files to debian. I downloaded them in
fedora.
but apt failed saying it could not contact
debian.deb to
gain access to the needed files.
Wait... you DID NOT chroot into the Debian file system after mounting it?!
How in the hell did you expect ANYTHING to work...?
No, I was not trying to use Debian commands from Fedora. I was in the
Debian emergency shell. I am no system admin, but I do know that won't work.
As it turns out dpkg failed because of other problems. A bunch of files
and directories related to sudo had been changed to being owned by me
instead of root. This I absolutely do not understand!! I had to fix them
one by one in the Debian emergency shell.
OK, basic primer:
mkdir /debian
mount /dev/whatever /debian
chroot /debian
There's fancy crap you can do involving bind mounts of /proc and so on,
but you probably don't need all that.
That said, I think you've jumped ahead too far. Your Debian system
apparently boots just fine -- it just doesn't run X.
That wasn't the problem. Seemingly it ran X but lightdm didn't run so X
was killed. That's what it looked like.
So boot Debian,
either normally, or with the "systemd.unit=multi-user.target" kernel
parameter, login on a regular text console, and fix it from there.
Once I fixed the sudo problem, dpkg worked and I reinstalled lightdm
and the greeter it uses. The system then booted fine but I have no idea
how it got into that state.
Another thing you could try would be to boot your previous kernel, in
case it was a kernel update that broke lightdm. It might not make any
difference, but hey, it's worth trying.
Another other thing you could try would be to run 'startx' from a
regular text console after booting Debian and logging in on said console.
If X starts correctly that way, then you know the problem is truly in
the DM, not in X, video drivers, video firmware, etc. We suspect this
already, but confirmation is always good.
These are good ideas I will try then next time I have a similar
problem, hopefully never.
Thanks for all your help and advice.
--
Frank McCormick
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