Bug#790743: systemd: Multiseat is not working after upgrade of systemd from 215-17 to 220-7

[Alberto]

Package: systemd
Version: 221-1
Severity: normal

Dear Maintainer,

I have a machine with 2 nvidia graphic cards, configured as multiseat, with 2
seats.
Debian is version testing (stretch). I use nouveau driver for nvidia cards.
The output of "loginctl seat-status seat1" is normal.

This Monday, during an upgrade, systemd was updated from version 215-17 to
220-7. After that multiseat stopped working.
X server for seat1 is not started.
Using keyboard on seat1 affects seat0. The mouse does not have this behaviour.
Downgrade to 215-17 is a nightmare due too many dependencies.

I tried:
- loginctl flush-devices and the loginctl attach to redo multiseat
configuration
- move of keyboard and mouse on another usb ports
- change of desktop manager (from gdm3 to lightdm)
- upgrade of systemd to 221-1 from unstable
- search on internet for known bugs or anomalies


Regards



-- Package-specific info:

-- System Information:
Debian Release: stretch/sid
  APT prefers testing
  APT policy: (500, 'testing'), (400, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/16 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages systemd depends on:
ii  adduser         3.113+nmu3
ii  libacl1         2.2.52-2
ii  libapparmor1    2.9.2-3
ii  libaudit1       1:2.4.2-1
ii  libblkid1       2.26.2-6
ii  libc6           2.19-18
ii  libcap2         1:2.24-9
ii  libcap2-bin     1:2.24-9
ii  libcryptsetup4  2:1.6.6-5
ii  libgcrypt20     1.6.3-2
ii  libkmod2        20-1
ii  liblzma5        5.1.1alpha+20120614-2+b3
ii  libmount1       2.26.2-6
ii  libpam0g        1.1.8-3.1
ii  libseccomp2     2.2.1-2
ii  libselinux1     2.3-2+b1
ii  libsystemd0     221-1
ii  mount           2.26.2-6
ii  sysv-rc         2.88dsf-59.2
ii  udev            220-7
ii  util-linux      2.26.2-6

Versions of packages systemd recommends:
ii  dbus            1.8.18-1
ii  libpam-systemd  221-1

Versions of packages systemd suggests:
ii  systemd-ui  3-4

-- debconf-show failed