Dragging the top activities/time bar freezes GNOME completely (Xorg session)

Next time the problem happens please switch to a virtual console and run:

  journalctl -b0 > journal.txt

and attach the resulting text file here.

The issue's really consistent and easy to reproduce thankfully.

When you say the workaround is to "kill the current program" do you mean the foreground app or the shell?

The foreground app.

By running "(journalctl -f > journal.txt &) && (nautilus &) && sleep 10 && killall nautilus && sleep 1 && killall journalctl", I was able to acquire only the log entries that occurred while reproducing the bug.

Oct 02 11:12:33 user-83BV systemd[1701]: Started tracker-extract-3.service - Tracker metadata extractor.
Oct 02 11:12:42 user-83BV dbus-daemon[1774]: [session uid=1000 pid=1774] Activating service name='org.gnome.Nautilus' requested by ':1.41' (uid=1000 pid=2293 comm="/usr/bin/gnome-shell" label="unconfined")
Oct 02 11:12:42 user-83BV nautilus[35524]: Connecting to org.freedesktop.Tracker3.Miner.Files
Oct 02 11:12:42 user-83BV dbus-daemon[1774]: [session uid=1000 pid=1774] Successfully activated service 'org.gnome.Nautilus'
Oct 02 11:12:42 user-83BV gnome-shell[2293]: Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x2e00004
Oct 02 11:12:42 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:12:43 user-83BV gnome-shell[2293]: Can't update stage views actor <unnamed>[<MetaWindowActorX11>:0x55f32df50d10] is on because it needs an allocation.
Oct 02 11:12:43 user-83BV gnome-shell[2293]: Can't update stage views actor <unnamed>[<MetaSurfaceActorX11>:0x55f32d9e56d0] is on because it needs an allocation.
Oct 02 11:12:45 user-83BV wpa_supplicant[1164]: wlp0s20f3: PMKSA-CACHE-ADDED 9c:1c:12:04:5a:d4 0
Oct 02 11:12:46 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:12:52 user-83BV gnome-shell[2293]: Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x2e00112
Oct 02 11:12:52 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:12:53 user-83BV gnome-shell[2293]: Can't update stage views actor <unnamed>[<MetaWindowActorX11>:0x55f33221e540] is on because it needs an allocation.
Oct 02 11:12:53 user-83BV gnome-shell[2293]: Can't update stage views actor <unnamed>[<MetaSurfaceActorX11>:0x55f32ff14c70] is on because it needs an allocation.
Oct 02 11:12:55 user-83BV dbus-daemon[1774]: [session uid=1000 pid=1774] Activating via systemd: service name='org.freedesktop.Tracker3.Miner.Extract' unit='tracker-extract-3.service' requested by ':1.83' (uid=1000 pid=3211 comm="/usr/libexec/tracker-miner-fs-3" label="unconfined")
Oct 02 11:12:55 user-83BV systemd[1701]: Starting tracker-extract-3.service - Tracker metadata extractor...
Oct 02 11:12:55 user-83BV dbus-daemon[1774]: [session uid=1000 pid=1774] Successfully activated service 'org.freedesktop.Tracker3.Miner.Extract'
Oct 02 11:12:55 user-83BV systemd[1701]: Started tracker-extract-3.service - Tracker metadata extractor.
Oct 02 11:13:02 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead

This also happens with non-GTK applications like xclock:

Oct 02 11:22:27 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:22:27 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:22:27 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:22:27 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:22:27 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:22:27 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:22:27 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:22:27 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:22:33 user-83BV rtkit-daemon[1793]: Supervising 9 threads of 6 processes of 1 users.
Oct 02 11:22:33 user-83BV rtkit-daemon[1793]: Supervising 9 threads of 6 processes of 1 users.
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83BV gnome-shell[2293]: Meta.Rectangle is deprecated, use Mtk.Rectangle instead
Oct 02 11:23:21 user-83...

Those log messages are not relevant here. They are being tracked in bug 2034664 and bug 2007742.

This issue also occurs semi-randomly when making normal touchscreen motions. For instance, sometimes I'll be scrolling through a webpage, the suddenly Firefox will un-maximize itself (turning into a normal window), and the cursor will get locked into the drag state. As per this issue, the system is then rendered inoperative until I kill Firefox (the active window).

This however, is not consistently reproducible, where as dragging from the top bar will cause the issue 100% of the time. It is by no means uncommon though, it is actually quite annoying to have my entire system freeze up semi-regularly and require me to manually restart Firefox (in fact, it happened while writing this comment).

I have also done some more testing.
- Minimizing the active window (using wmctrl) from a virtual console does not solve the issue.
- Starting a new window from a virtual console does not solve the issue.
- Consistently, the only way to resolve this issue is the kill the active program.

The bug is even worse if you just tap on the top bar, rather than drag. If you just tap, the window will un-maximize and also get trapped in the "snap to half of screen / tiling hint" thingy (see attached screenshot).

It gets worse though. While normally killing the foreground program works around the bug and makes the system usable again, if you kill the program while also trapped in the tiling thingy, it will also crash GNOME entirely.

Here's the stack-trace:

Oct 09 15:30:50 user-83BV gnome-shell[335512]: Error in size change accounting.
Oct 09 15:30:50 user-83BV gnome-shell[335512]: **
Oct 09 15:30:50 user-83BV gnome-shell[335512]: libmutter:ERROR:../src/core/window.c:5469:meta_window_get_workspaces: code should not be reached
Oct 09 15:30:50 user-83BV gnome-shell[335512]: Bail out! libmutter:ERROR:../src/core/window.c:5469:meta_window_get_workspaces: code should not be reached
Oct 09 15:30:50 user-83BV gnome-shell[335512]: GNOME Shell crashed with signal 6
Oct 09 15:30:50 user-83BV gnome-shell[335512]: == Stack trace for context 0x5570e87f79d0 ==
Oct 09 15:30:50 user-83BV gnome-shell[335512]: #0 5570e88bee48 i file:///<email address hidden>/src/extension/tilingWindowManager.js:99 (2597789ad9c0 @ 78)
Oct 09 15:30:50 user-83BV gnome-shell[335512]: #1 5570e88bed70 i file:///<email address hidden>/src/extension/tilingWindowManager.js:1291 (2597789b45b0 @ 95)
Oct 09 15:30:50 user-83BV gnome-shell[335512]: #2 5570e88bece8 i file:///<email address hidden>/src/extension/tilingWindowManager.js:431 (2597789addd0 @ 17)
Oct 09 15:30:50 user-83BV gnome-shell[335512]: #3 5570e88bec58 i resource:///org/gnome/shell/ui/init.js:21 (1a1d6a070ba0 @ 48)

Here's the crash report: https://errors.ubuntu.com/oops/8eae4f20-66d9-11ee-9abb-fa163ec44ecd

Interesting. That assertion was meant to be fixed 3.5 years ago in bug 1845281. But it's definitely a different bug since that one is fatal and this one is not.

Also, I checked and this bug does not occur on Wayland.