Checking activation of different background picture

[elfring]

I am trying the software “LightDM GTK+ Greeter version 2.0.8-1.fc34” out.
The file “/etc/lightdm/lightdm-gtk-greeter.conf” contains the following specifications for my system.

…
background = /usr/share/backgrounds/default.png
…
user-background = false
…

This selected picture is displayed for a very short moment for login attempts.
But I am observing that it is immediately replaced by a different picture (which I am using for my XFCE user session for a while).
🤔 I wonder about this login image replacement when user backgrounds should not be applied at the moment.

[elfring]

Will another report trigger further development and configuration considerations accordingly?

[bluesabre]

The user-background setting seems to be working for me. It's possible that your lightdm-gtk-greeter.conf file is not being read. Can you paste the output of:

sudo grep "\.conf" /var/log/lightdm/seat*-greeter.log

It should look something like this.

$ sudo grep "\.conf" /var/log/lightdm/seat*-greeter.log
** Message: 03:38:00.484: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/01_ubuntu.conf
** Message: 03:38:00.484: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/30_xubuntu.conf
** Message: 03:38:00.484: [Configuration] Reading file: /usr/local/etc/lightdm/lightdm-gtk-greeter.conf
** Message: 03:38:34.040: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/01_ubuntu.conf
** Message: 03:38:34.040: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/30_xubuntu.conf
** Message: 03:38:34.040: [Configuration] Reading file: /usr/local/etc/lightdm/lightdm-gtk-greeter.conf
** Message: 03:40:04.539: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/01_ubuntu.conf
** Message: 03:40:04.539: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/30_xubuntu.conf
** Message: 03:40:04.539: [Configuration] Reading file: /usr/local/etc/lightdm/lightdm-gtk-greeter.conf
** Message: 03:47:10.131: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/01_ubuntu.conf
** Message: 03:47:10.131: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/30_xubuntu.conf
** Message: 03:47:10.131: [Configuration] Reading file: /usr/local/etc/lightdm/lightdm-gtk-greeter.conf

[elfring]

It's possible that your lightdm-gtk-greeter.conf file is not being read.

Why would such a questionable software behaviour happen (while I could look at available settings by some tools)? 🤔

[bluesabre]

It could happen as a result of how software is packaged and installed. The greeter reads from multiple files. The tools that write the configuration only write to a single file. If they're not using the same files, changing settings won't work reliably if at all.

[elfring]

🤔

• Can such information be clarified any further?
• Would you like to share more experiences about questionable behaviour in affected software areas?

[bluesabre]

It's intentional behavior, intended to support distributions. In my output above,

** Message: 03:47:10.131: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/01_ubuntu.conf
** Message: 03:47:10.131: [Configuration] Reading file: /usr/share/lightdm/lightdm-gtk-greeter.conf.d/30_xubuntu.conf
** Message: 03:47:10.131: [Configuration] Reading file: /usr/local/etc/lightdm/lightdm-gtk-greeter.conf

You can see that the greeter is reading each configuration file in order from /usr/share/lightdm/lightdm-gtk-greeter.conf.d. It's also reading from /usr/local/etc/lightdm/lightdm-gtk-greeter.conf because my local copy was installed to the /usr/local/ prefix. If it was installed without a prefix, it would read from /etc/lightdm/lightdm-gtk-greeter.conf instead.

Because my greeter is installed to /usr/local but the settings manager is installed without a prefix, I have the scenario where the settings manager is writing to /etc/lightdm/lightdm-gtk-greeter.conf but the greeter isn't reading it. I created a symbolic link between /usr/local/etc/lightdm/lightdm-gtk-greeter.conf and /etc/lightdm/lightdm-gtk-greeter.conf to ensure they're using the same file.

To summarize, if the settings are not applying but you are using the versions of the software packaged by Fedora, you should consider reporting a bug on the Fedora bug tracker instead.

[elfring]

To summarize, if the settings are not applying but you are using the versions of the software packaged by …

Did you hear about any related open issues (and corresponding adjustments) for available software distributions?

[bluesabre]

No. Everything seems to be working here, at least on Xubuntu. Please paste the output of

sudo grep "\.conf" /var/log/lightdm/seat*-greeter.log

or I will not be able to assist you further.

[elfring]

💭 I hope that software distributions will improve their packages (also for this issue).