[regression] gnome-shell crashes if booted with the monitor off ["JS ERROR: TypeError: monitor is null" from _updateContentScale@resource:///org/gnome/shell/ui/magnifier.js:174:9]

Seems it's not an upstream bug:
https://gitlab.gnome.org/GNOME/gnome-shell/issues/1225

This bug was fixed in the package gnome-shell - 3.32.1-1ubuntu1

---------------
gnome-shell (3.32.1-1ubuntu1) eoan; urgency=medium

  [ Marco Trevisan (Treviño) ]
  * Merge with debian
    - Update to 3.32.1 upstream version (LP: #1826936)
    - Fixes Icon disappears from favorites (LP: #1822846)
    - Fix applications aren't focused in Wayland session (LP: #1826176)
    remaining changes:
    + Replace gnome-backgrounds dep with ubuntu-wallpapers and Suggests
      gnome-themes-standard-data, gnome-backgrounds
    + Add some Recommends:
      - ubuntu-session (| gnome-session) to have the ubuntu session available
      - xserver-xorg-legacy
      - yaru-theme-gnome-shell for the default ubuntu theming
    + Update debian/gbp.conf with Ubuntu settings
    + gnome-shell-common.install: Install Ubuntu mode
    + gnome-shell-common.prerm: Remove deprecated ubuntu theme alternative
    + ubuntu/desktop_detect.patch:
      - add caching for desktop detection to avoid querying the current
        desktop env variable as iterate through the list each time. For the
        time of the Shell process, we can expect this env variable to stay
        stable.
    + ubuntu/smarter_alt_tab.patch:
      - quick alt-tab (without showing up the switcher) switch only between
        the last window of the last 2 applications to be focused instead of
        raising all windows of those apps.
    + ubuntu/lightdm-user-switching.patch:
      - Allow user switching when using LightDM.
    + ubuntu/lock_on_suspend.patch
      - Respect Ubuntu's lock-on-suspend setting.
    + ubuntu/gdm.patch
      - as gdm is system-wide and not session-wide, ensure gdm has an ubuntu
        styling by default, not impacting the gnome user session though.
    + ubuntu/background_login.patch
      - Change default background color as we modified the default GDM color
        for our ubuntu session. Change it as well here, still applying the
        background noise loading.
    + ubuntu/gdm_alternatives.patch
      - Add support for GDM3 theme alternatives
    + ubuntu/block_mode_extension_update.patch
      - Don't allow ubuntu mode extension to update
    + optional-hot-corner.patch
      - enable patch proposed by upstream developer already in package (but
        not in series) to add a settings for optional hot corner activation.
    + volume-Add-back-sound-feedback-on-scroll.patch
      - Fix regression causing missing feedback on volume slider scroll
    + main-show-an-error-message-on-gnome-shell-crash.patch,
      global-make-possible-to-set-debug-flags-dynamically.patch,
      main-increase-the-granularity-of-backtraces-in-SHELL_DEBU.patch,
      main-add-backtrace-crashes-all-and-backtrace-all.patch,
      sessionMode-add-support-for-debugFlags-parameter.patch:
      - Improve debug JS tracing for crash reports
    + st-scroll-view-Handle-the-case-where-scrollbars-are-NULL.patch,
      st-scroll-view-Remove-scrollbars-references-on-dispose.patch:
      - Fix crash on theme changes
    + ubuntu/search-call-XUbuntuCancel-method-on-providers-when-no-dat.patch:
      - stop searches when requested from UI
    + magnifier-Show-cursor-when-magnifier-is-enabled-and-scale.patch:...

Hello Daniel, or anyone else affected,

Accepted gnome-shell into disco-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/gnome-shell/3.32.1-1ubuntu1~19.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-disco to verification-done-disco. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-disco. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

I no longer have a desktop running disco with which to test this :/

You can't test it on a laptop...

Tested with gnome-shell 3.32.0+git20190410-1ubuntu1

This bug was fixed in the package gnome-shell - 3.32.1-1ubuntu1~19.04.1

---------------
gnome-shell (3.32.1-1ubuntu1~19.04.1) disco; urgency=medium

  * Backport from eoan to disco
  * Update VCS metadata

gnome-shell (3.32.1-1ubuntu1) eoan; urgency=medium

  [ Marco Trevisan (Treviño) ]
  * Merge with debian
    - Update to 3.32.1 upstream version (LP: #1826936)
    - Fixes Icon disappears from favorites (LP: #1822846)
    - Fix applications aren't focused in Wayland session (LP: #1826176)
    remaining changes:
    + Replace gnome-backgrounds dep with ubuntu-wallpapers and Suggests
      gnome-themes-standard-data, gnome-backgrounds
    + Add some Recommends:
      - ubuntu-session (| gnome-session) to have the ubuntu session available
      - xserver-xorg-legacy
      - yaru-theme-gnome-shell for the default ubuntu theming
    + Update debian/gbp.conf with Ubuntu settings
    + gnome-shell-common.install: Install Ubuntu mode
    + gnome-shell-common.prerm: Remove deprecated ubuntu theme alternative
    + ubuntu/desktop_detect.patch:
      - add caching for desktop detection to avoid querying the current
        desktop env variable as iterate through the list each time. For the
        time of the Shell process, we can expect this env variable to stay
        stable.
    + ubuntu/smarter_alt_tab.patch:
      - quick alt-tab (without showing up the switcher) switch only between
        the last window of the last 2 applications to be focused instead of
        raising all windows of those apps.
    + ubuntu/lightdm-user-switching.patch:
      - Allow user switching when using LightDM.
    + ubuntu/lock_on_suspend.patch
      - Respect Ubuntu's lock-on-suspend setting.
    + ubuntu/gdm.patch
      - as gdm is system-wide and not session-wide, ensure gdm has an ubuntu
        styling by default, not impacting the gnome user session though.
    + ubuntu/background_login.patch
      - Change default background color as we modified the default GDM color
        for our ubuntu session. Change it as well here, still applying the
        background noise loading.
    + ubuntu/gdm_alternatives.patch
      - Add support for GDM3 theme alternatives
    + ubuntu/block_mode_extension_update.patch
      - Don't allow ubuntu mode extension to update
    + optional-hot-corner.patch
      - enable patch proposed by upstream developer already in package (but
        not in series) to add a settings for optional hot corner activation.
    + volume-Add-back-sound-feedback-on-scroll.patch
      - Fix regression causing missing feedback on volume slider scroll
    + main-show-an-error-message-on-gnome-shell-crash.patch,
      global-make-possible-to-set-debug-flags-dynamically.patch,
      main-increase-the-granularity-of-backtraces-in-SHELL_DEBU.patch,
      main-add-backtrace-crashes-all-and-backtrace-all.patch,
      sessionMode-add-support-for-debugFlags-parameter.patch:
      - Improve debug JS tracing for crash reports
    + st-scroll-view-Handle-the-case-where-scrollbars-are-NULL.patch,
      st-scroll-view-Remove-scrollbars-references-on-dispose.patch:
      - Fix crash on theme changes
    + ubuntu/search-call-XUbuntuCancel-method-on-providers-when-no-...

The verification of the Stable Release Update for gnome-shell has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.