startDM debugging - SOLVED

[jankom]

02/21/2023 edit by jankom: marked SOLVED, see p 2, last post.

I have customized my gentoo desktop installation (profile 5) to boot with slim login display manager with twm session. It has been working for awhile, but recently I notice an error message at the "default" stage of setting up services: ... yourXDM value is invalid... This comes from /etc/init.d/display-manager script which is basically a collection of functions. So I try to understand the boot process, what calls what, step-by-step. Despite the error message everything is fine, twm works, and exiting twm I can "halt" or "reboot" from slim with root pw.

It looks like the startDM defines tbe service name as "display-manager". My simple question: where is the "get-options" function or command that sets up the X environment for startDM or the display-manager service?

part of the startDM script is here:

[grknight]

"get_options" is an OpenRC built-in command, which lives in /lib/rc/bin, to retrieve items set by "save_options" or "service_set_value"

Technically, it can be used outside of an OpenRC service by using the RC_SVCNAME environment variable to query any service's saved settings.

[jankom]

Thanks - understood. I continue my debugging to eliminate the error message, or as how to configure my system cleanly.

jankom/janos

[GDH-gentoo]

[jankom]

[GDH-gentoo]

That looks correct. The message you see comes from the execution of this case ... esac branch:

/etc/init.d/display-manager

[jankom]

Yes, /etc/init.d/display-manager is a collection of functions that /usr/bin/startDM calls while startDM sets up the start-stop-daemon

Also, when I halt or reboot the shutting down process produces another error message on the console that "No matching service found" or something close while stopping various services for shut down.

As far as the output of that command is concerned:

[colo-des]

If you look at the differences between the ebuilds xinit-1.4.1-r1.ebuild and xinit-1.4.1.ebuild, using diff or meld.

[jankom]

@colo-des: interesting and thank you. If I understand correctly the emerge --sync created the otherwise innocent error messages on the console.

As far as debugging is concerned here is an update how far I got.

(1) display-manager
I put some printf statements in it, and yes, the MY_XDM value is correctly defined as "slim" (probably from /etc/confd). However, because "slim" is not one of the case stanza in the display-manager script the variable EXE is blank, leading to the innocent error message, True, the comment section of /etc/conf.d/display-manager file does not include slim as a legitimate choice - and I understand why: because slim has not been maintained for awhile. Btw, this script is run from openrc-run executable.

(2) startDM
I tried the same method of debugging to see what is happening, but neither printf nor eerror produced anything. The startDM in /usr/bin is mentioned in the last line of inittab. Actually, /usr/bin/startDM is a simple script using info provided by item (1) above: display-manager, and it initiates the start-stop-daemon for starting the specified MY_XDM, prepared by the process in (1) above. Since it could not populate the start-stop-daemon no daemon is started, and that explains the other innocent shotdown error message of "no mathing service...".

So my question: how come slim is still working including my twm?

Additional info:

[colo-des]

The display-manager-init package is a non-standard creation by gentoo developers.

https://gitweb.gentoo.org/repo/gentoo.git/tree/gui-libs/display-manager-init/display-manager-init-1.1.2.ebuild

The problem is for those who want the standard method of a lifetime.

https://forums.gentoo.org/viewtopic-p-8767736.html#8767736

Greetings.

[GDH-gentoo]

[jankom]

Thank you, thank you. This forum is the best (best people posting)f

[GDH-gentoo]

[jankom]

OK, I'm a slow leaner but getting there.

[GDH-gentoo]

[jankom]

I've studied all posts in this thread, and modified the display-manager script:

[colo-des]

What is the reason to forcefully replace xdm with display-manager-init ?

Why would I stop using the xdm standard for something new that brings me complications ?

The solution is to stick with xdm by putting it in the local tree, but soon you'll have to do the same with slim
because if they don't find a way to make people stop using it, they will remove it from the official tree.

This is the game of cat and mouse and forgive me but what is at stake here is freedom of choice
what to use and how to use, the options on the tray are chosen by few people and the rest to obey ?.

This is shocking and it's a break, that's why I've told that I'm migrating from gentoo to lfs/blfs with package creation
binaries with their own crux-type ports where updating is no longer an obligation imposed by the distro
but because of the dependencies that one regulates by creating one's own ports.
I have already created 227 ports and many are missing but very happy for the total control I have now.

[grknight]

[colo-des]

If it were just the name change, its operation should be the same and even in its MD5, but this is not the case.
I do not want to leave the standard of a lifetime but they forced in this way to accept the game or to abandon the game.

My local tree is a mess of EAPI changes with their eclass...all to create incompatibilities and make the install no longer work.

I do not criticize... I only expose, but for my part... I have abandoned the game.

[GDH-gentoo]

[jankom]

Interesting discussion about freedom of choice. Yes, and I prefer simplicity. I'd rather be in the driver's seat than sitting in the bus.

* When I boot the first thing is the slim login screen. I can login as user with pw or halt / reboot with root pw.

* After login as user my gui environment screen is presented, and the right click / left click menus of twm are active. This is my favorite gui environment, totally customized to my liking.

* While in my gui environment command top indicates that only X and slim are running (besides ini and some services set up for default run level). The interesting part is that according to top display-manager is nut running while "rc-service display-manager status" says it started. This explains the shutdown error message that the service was not found.

* My gui environment is defined and customized with my own decoration and twm menu system in the ~/.xsession file. This comes from /etc/X11/Sessions/Xsession.

If ~/.xsession file is not there I can create an ~/.Xclients file with a different X window decoration (programs started, running, background, etc.).

If ~/ has neither .xsession nor .Xclients file then $failsafe X window opens up with just an xterm in the top left corner and no decoration. The variable failsafe is defined by /etc/X11/Sessions/Xsession.

In the failsafe gui environment I can issue a "twm &" command in xterm which will make the twm right click / left click menu system available. Exiting twm stops the menu system.

If I issue the exit command in xterm it looks like X shuts down (briefly showing console) and the gui slim login screeen is presented.

Conclusion: display-manager starts slim based on the display-manager variable defined in /etc/confd, slim starts X.

I still don't understand how and when EXE is defined.
(a) if slim is not in the case-esac part of display-manager script XDM error is displayed because there is no EXE variable, yet slim starts.
(b) if slim is edited into case-esac then EXE is non-zero and no more XDM error.
What makes EXE non-zero?

jankom/janos

[GDH-gentoo]

[Hu]

Since this file is in /etc/init.d, it would be subject to CONFIG_PROTECT. Perhaps at some point that file on this system was modified in a way that Portage ceased to automatically replace it on updates, and a subsequent etc-update was either missed or executed incorrectly, such that /etc/init.d/display-manager on this system now is not what would be installed there on a clean system. If so, forcing Portage to reinstall the clean copy, and merging in any intentional local modifications, might fix this.

[jankom]

Thank you both.
I definitely would like a clean system, especially because I manage two Gentoo installations: one at my home on a fitlet2 core and the other, a virtual server having its own public IP. That latter is my vpn host.
Please, help me to issue the proper commands. Yes, I may have inadvertently messed up something. On fitlet, my home machine, "eix-test-obsolete" complains:

[GDH-gentoo]

For starters, I would emerge --oneshot gui-libs/display-manager-init, and see if this overwrites /etc/init.d/display-manager with a clean copy. You might have to do an etc-update after that, Portage will tell you if you must.
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