Bug#926316: systemd: Installing the systemd package switches the init system to systemd

[Emmanuel Bourg]

Package: systemd
Version: 241-1
Severity: normal

Hi,

The description of the systemd package states that installing it will not
switch the init system, unfortunately that's what happens, unless systemd
is installed with --no-install-recommends. It looks like a recommended
dependency (libpam-systemd?) triggers the removal of sysvinit-core.

I haven't been able to track exactly why it happens in testing with the
version 241-1. With the version 241-2 in sid I guess the removal of
systemd-shim from the alternative dependencies of libpam-systemd [1]
last week doesn't help.


    root at sysvinit:~# ps aux
    USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
    root         1  0.0  0.0   7900  1980 pts/1    Ss+  09:29   0:00 init [2]
    root       884  0.0  0.1 156188  2412 ?        Ssl  09:29   0:00 /usr/sbin/rsyslogd
    root       912  0.0  0.0   5508  1968 ?        Ss   09:29   0:00 /usr/sbin/cron
    root       940  0.0  0.1   4000  3300 ?        Ss   09:29   0:00 /bin/bash
    root      1237  0.0  0.0   2420  1480 pts/0    Ss+  09:31   0:00 /sbin/getty --noclear 38400 tty1
    root      1238  0.0  0.0   2420  1556 pts/1    Ss+  09:31   0:00 /sbin/getty --noclear 38400 tty2
    root      2269  0.0  0.1   7640  2724 ?        R+   09:53   0:00 ps aux

    root at sysvinit:~# ls -l /sbin/init
    -rwxr-xr-x 1 root root 53016 Feb 14 20:33 /sbin/init

    root at sysvinit:~# apt install systemd
    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    The following packages were automatically installed and are no longer required:
      initscripts insserv startpar sysv-rc
    Use 'apt autoremove' to remove them.
    The following additional packages will be installed:
      dbus libargon2-1 libcryptsetup12 libdbus-1-3 libexpat1 libjson-c3 libnss-systemd libpam-systemd systemd-sysv
    Suggested packages:
      default-dbus-session-bus | dbus-session-bus systemd-container policykit-1
    The following packages will be REMOVED:
      sysvinit-core
    The following NEW packages will be installed:
      dbus libargon2-1 libcryptsetup12 libdbus-1-3 libexpat1 libjson-c3 libnss-systemd libpam-systemd systemd systemd-sysv
    0 upgraded, 10 newly installed, 1 to remove and 0 not upgraded.
    Need to get 4786 kB of archives.
    After this operation, 16.7 MB of additional disk space will be used.
    Do you want to continue? [Y/n] n
    Abort.

    root at sysvinit:~# apt install systemd --no-install-recommends
    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    The following additional packages will be installed:
      libargon2-1 libcryptsetup12 libjson-c3
    Suggested packages:
      systemd-container policykit-1
    Recommended packages:
      libpam-systemd dbus
    The following NEW packages will be installed:
      libargon2-1 libcryptsetup12 libjson-c3 systemd
    0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
    Need to get 3733 kB of archives.
    After this operation, 14.4 MB of additional disk space will be used.
    Do you want to continue? [Y/n] n
    Abort.

Emmanuel Bourg

[1] https://salsa.debian.org/systemd-team/systemd/commit/8d292a0a