Bug#956894: upgrade-reports: display of gnome login screen failed /gnome crashes after applying dist-upgrade on 16th of April 2020

Package: upgrade-reports
Severity: important

Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

   * What led up to the situation?
   Since today's dist-upgrade Gnome does not start to lock screen and crashes before. Graphical error message is displayed.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?
   Checked journalctl /usr/bin/gnome-shell(-session) logs for gnome realted issues: Since the update I see a assertion failed for "gnome_bg_slide_show_set_property" in "gnome-bg-slide_show.c:83"
   g_once_init_leave: assertion: 'result!=0' failed
   Can not register existing type 'GnomeBGSlideShow'

   * What was the outcome of this action?
   I have not taken any action yet as I currently don't exactly know why this issue occures

   * What outcome did you expect instead?


-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 5.5.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled