Bug#934491: libelogind0: failing to switch from systemd to sysvinit-core/elogind results in libsystemd.so.0 disappearing

[Cristian Ionescu-Idbohrn]

On Sat, 21 Sep 2019, Mark Hindley wrote:
> 
> Removing the pending tag as I don't think there is anything for 
> elogind to do to fix this.

Hi,

I'm interested in this, but my systems (unstable and testing) are in a 
slightly different state.  Let's take unstable, for example:

,----
| # apt-cache policy systemd-sysv
| systemd-sysv:
|   Installed: (none)
|   Candidate: (none)
`----

,----
| # apt-cache policy sysvinit-core 
| sysvinit-core:
|   Installed: 2.96~beta-1
|   Candidate: 2.96~beta-1
`----

,----
| # apt-cache policy systemd
| systemd:
|   Installed: 238-5
|   Candidate: 238-5
`----

(that is an older version).  And that's because i have:

,----
| # cat /etc/apt/preferences.d/no-systemd 
| Package: systemd systemd-sysv libsystemd0 libpam-systemd 
| Pin: release o=Debian
| Pin-Priority: -1
`----

So, pid 1 is already:

,----
| -rwxr-xr-x 1 root root 53176 Aug 24 16:46 /sbin/init
`----

Systemd stuff was forcibly installed, but systemd is _not_ pid 1.

Attempting to install:

,----
| # apt-get install libpam-elogind elogind libelogind0
`----

gives me a list of:

,----
| 4 upgraded, 3 newly installed, 97 to remove and 146 not upgraded.
`----

Most of the packages to be removed are kde-related:

,----
| The following packages will be REMOVED:
|   akonadi-server breeze drkonqi ffmpegthumbs frameworkintegration k3b
|   kactivitymanagerd kaffeine kamera kamoso kcachegrind kde-cli-tools
|   kde-config-cddb kde-config-screenlocker kde-runtime kde-style-breeze
|   kdeconnect kdelibs5-plugins kdesudo kinit kio kmahjongg kmenuedit kommander
|   kpat krusader kwin-common kwin-style-breeze libcolorcorrect5 libk3b7
|   libkf5akonadicore5abi2 libkf5akonadiwidgets5abi1 libkf5auth5 libkf5authcore5
|   libkf5bookmarks5 libkf5cddb5 libkf5configwidgets5 libkf5declarative5
|   libkf5iconthemes5 libkf5kcmutils5 libkf5kdegames7 libkf5kdelibs4support5
|   libkf5kdelibs4support5-bin libkf5kiocore5 libkf5kiofilewidgets5
|   libkf5kiogui5 libkf5kiowidgets5 libkf5kmahjongglib5 libkf5newstuff5
|   libkf5newstuffcore5 libkf5notifyconfig5 libkf5parts5 libkf5plasma5
|   libkf5plasmaquick5 libkf5purpose-bin libkf5purpose5 libkf5quickaddons5
|   libkf5runner5 libkf5sane5 libkf5style5 libkf5texteditor-bin
|   libkf5texteditor5 libkf5textwidgets5 libkf5wallet-bin libkf5xmlgui5
|   libkf5xmlrpcclient5 libkscreenlocker5 libkwin4-effect-builtins1
|   libokular5core8 libpam-systemd libpolkit-backend-1-0 libpolkit-qt-1-1
|   libpolkit-qt5-1-1 libprocessui7 libsystemd0 libtaskmanager6 libweather-ion7
|   milou okular plasma-desktop plasma-framework plasma-integration
|   plasma-workspace polkit-kde-agent-1 qml-module-org-kde-draganddrop
|   qml-module-org-kde-kconfig qml-module-org-kde-kcoreaddons
|   qml-module-org-kde-kquickcontrols qml-module-org-kde-kquickcontrolsaddons
|   qml-module-org-kde-kwindowsystem qml-module-org-kde-purpose
|   qml-module-org-kde-qqc2desktopstyle rasdaemon skanlite skrooge systemd
|   udisks2
`----

but not only (some *polkit* among them, I guess kde-related).  Of
course I could let them be removed and later reinstall them.  But
that's not smooth/optimal.

Still:

,----
| The following additional packages will be installed:
|   gir1.2-polkit-1.0 libpolkit-agent-1-0 libpolkit-gobject-1-0 policykit-1
`----

Looking deeper I notice both libelogind0 and libpam-elogind provide a 
certain version of systemd packages:

,----
| Package: libelogind0
| Provides: libsystemd0 (= 241.3)
`----

,----
| Package: libpam-elogind
| Provides: logind (= 241.3-1+debian1)
`----

but can't help wondering if that is necessary/relevant.  Shouldn't 
they provide _any_ current version of libsystemd0 and logind and 
remove _any_ earlier versions?  Isn't installing the current versions 
of systemd-related packages an unnecessary step?


Cheers,

-- 
Cristian