Bug#999596: sddm unnecessarily starts pulseaudio with sytemd user serssion

[Patrick Häcker <pat_h@web.de>]

Package: sddm
Version: 0.19.0-3
Severity: normal

Dear Maintainer,

I am not really sure, if this is a sddm, pulseaudio or systemd bug, as all
three seem somehow involved:

Pulseaudio installs pulseaudio.service and pulseaudio.socket below
/usr/lib/systemd/user/ i.e. pulseaudio is started for every systemd user
session. As sddm is started with the user sddm, this starts a systemd user
session and therefore sddm starts pulseaudio.

This seems to be totally unnecessary, and leads to a warning when logging in
with the normal user. The shortened output of
"journalctl --priority warning --boot --output verbose" contains
    PRIORITY=4
    _TRANSPORT=journal
    _UID=121
    _GID=142
    _AUDIT_LOGINUID=121
    _SYSTEMD_OWNER_UID=121
    _SYSTEMD_SLICE=user-121.slice
    _SYSTEMD_UNIT=user@121.service
    _PID=1010
    MESSAGE=After module unload, module 'module-null-sink' was still loaded!
    CODE_FILE=../src/pulsecore/module.c
    CODE_FUNC=pa_module_unload_all
    CODE_LINE=367
    SYSLOG_IDENTIFIER=pulseaudio
    _COMM=pulseaudio
    _EXE=/usr/bin/pulseaudio
    _CMDLINE=/usr/bin/pulseaudio --daemonize=no --log-target=journal
    _SYSTEMD_CGROUP=/user.slice/user-121.slice/user@121.service/session.slice/pulseaudio.service
    _SYSTEMD_USER_UNIT=pulseaudio.service
    _SYSTEMD_USER_SLICE=session.slice
I confirmed that user sddm has a pulseaudio process running when no user is
logged in with SDDM.

sddm should most probably not start pulseaudio at all and maybe also not all
the other services in a systemd user session and possibly no systemd user
session in the beginning.

Kind regards
Patrick

-- System Information:
Debian Release: bookworm/sid
  APT prefers stable-security
  APT policy: (900, 'stable-security'), (900, 'testing'), (800, 'stable'), (500, 'unstable-debug'), (400, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 5.14.0-2-amd64 (SMP w/4 CPU threads)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de:en_US
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages sddm depends on:
ii  adduser                   3.118
ii  debconf [debconf-2.0]     1.5.79
ii  libc6                     2.32-4
ii  libgcc-s1                 11.2.0-10
ii  libpam0g                  1.4.0-10
ii  libqt5core5a              5.15.2+dfsg-12
ii  libqt5dbus5               5.15.2+dfsg-12
ii  libqt5gui5                5.15.2+dfsg-12
ii  libqt5network5            5.15.2+dfsg-12
ii  libqt5qml5                5.15.2+dfsg-8
ii  libqt5quick5              5.15.2+dfsg-8
ii  libstdc++6                11.2.0-10
ii  libsystemd0               249.5-2
ii  libxcb-xkb1               1.14-3
ii  libxcb1                   1.14-3
ii  qml-module-qtquick2       5.15.2+dfsg-8
ii  x11-common                1:7.7+23
ii  xauth                     1:1.1-1
ii  xserver-xephyr [xserver]  2:1.20.11-1
ii  xserver-xorg [xserver]    1:7.7+23
ii  xvfb [xserver]            2:1.20.11-1

Versions of packages sddm recommends:
pn  haveged                                <none>
ii  libpam-systemd                         249.5-2
ii  sddm-theme-breeze [sddm-theme]         4:5.23.2-1
ii  sddm-theme-debian-breeze [sddm-theme]  4:5.23.2-1
ii  sddm-theme-debian-elarun [sddm-theme]  0.19.0-3
ii  sddm-theme-debian-maui [sddm-theme]    0.19.0-3
ii  sddm-theme-maya [sddm-theme]           0.19.0-3

Versions of packages sddm suggests:
ii  libpam-kwallet5           5.23.2-1
pn  qtvirtualkeyboard-plugin  <none>

-- Configuration Files:
/etc/pam.d/sddm changed [not included]

-- debconf information:
* shared/default-x-display-manager: sddm
  sddm/daemon_name: /usr/bin/sddm