Score:3

Upgrade from 20.04 to 22.04 fails, missing gdm-password file

nz flag

I finally tried to upgrade from Ubuntu 20.04 LTS to 22.04 LTS. Unfortunately, update manager fails to complete the process. When I run the update-manager manually I get the following error message:

FileNotFoundError: [Errno 2] No such file or directory: '/etc/pam.d/gdm-password'

When I check the above mentioned folder, there is a symlink gdm-password -> gdm but there is no actual gdm -file. There is, however, a file named gdm-password.dpkg-new from the year 2020. This is probably from when I upgraded from 18.04 to 20.04. Is this just a naming problem or something else?

Can anyone help me with this error? Is this gdm-password -file really needed since my system seems to be working fine without it? Only the upgrade fails.

To be complete, I have already done

sudo apt update && sudo apt upgrade

and there seems to be no package related problems. Only this gmd-password error remains.

Score:3
jp flag

When I check the above mentioned folder, there is a symlink gdm-password -> gdm

That file should be a gdm3 password policy/configuration file:

$ dpkg -S /etc/pam.d/gdm-password
gdm3: /etc/pam.d/gdm-password

and should not be a symbolic-link:

$ file /etc/pam.d/gdm-password
/etc/pam.d/gdm-password: ASCII text

You can, as well, verify that with:

$ apt download gdm3 && dpkg --contents gdm3* | grep gdm-password
Get:1 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 gdm3 amd64 42.0-1ubuntu7.22.04.3 [314 kB]
Fetched 314 kB in 1s (278 kB/s)
-rw-r--r-- root/root      1320 2023-06-01 13:37 ./etc/pam.d/gdm-password

To fix that, remove the current symlink like so:

sudo rm /etc/pam.d/gdm-password

Then reinstall gdm3 to recreate that file the right and easy way like so:

sudo apt install --reinstall gdm3
Score:1
nz flag

I got this working by removing gnome-shell-common and gdm3 and everything related to them.

I managed to get the upgrade going following these instructions:

https://discourse.ubuntubudgie.org/t/upgrade-from-20-04-to-22-04-fails-missing-gdm-password-file/6763

EDIT: I'm using Mate Desktop with my Ubuntu installation. Since it uses lightdm and not gdm3, this solution works. I suppose the suggestion with reinstalling gdm3 would be needed if I used the "normal" Ubuntu desktop. So use this only with Desktops using lightdm.

Raffa avatar
jp flag
I wounder ... If you use **Budgie** ... Why didn't you mention that in your question?
ToniKH avatar
nz flag
Actually, I'm not using Budgie. I posted my question to that forum also, because there were some similar kind of discussions there. And it turns out they found the solution that worked with me also. I'm using Ubuntu with Mate desktop and it turned out I don't need gdm3. That was something I didn't know.
Raffa avatar
jp flag
Or **Mate** ... Each flavor might have it's own different Login Manager "GDM, LightDM ... etc." and we call [flavors](https://ubuntu.com/desktop/flavours) by their names here and Ubuntu means the one with Gnome and GDM ... Anyway, **Welcome to Ask Ubuntu** and please add that info to your answer in a clear way as the solution provided in your answer if applied by an Ubuntu desktop user will render their system unusable.
ToniKH avatar
nz flag
Thank you for the clarification! I was a bit confused with these different display managers. The problem was that my installation is a normal Ubuntu installation, but I only use Mate desktop with it. I didn't realize this counts as a different flavour, since there is also a pure Ubuntu Mate installation, which this is not. But I'm glad things are working now! (Let's hope everything still works after upgrade :) ) I also edited my answer with this information!
ToniKH avatar
nz flag
I can now verify that the upgrade went well this way. Everything seems to be working the way it was before, there was no more problems with the upgrade. Pretty nice, since this is a quite old system. I have now upgraded all the way from at least 16.04, maybe even 14.04.
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