Keyboard settings crash with "Segmentation Fault" when opening Layout Options

Distribution

mint 22.1

Package version

Cinnamon 6.4.8

Graphics hardware in use

NVIDIA Corporation GM108M [GeForce 840M]

Frequency

Always

Bug description

Hello Cinnamon development team,

I am experiencing a consistent crash in the System Settings panel. Specifically, the "Keyboard" settings window closes immediately with a Segmentation fault whenever I try to access the "Options..." button within the "Layouts" tab.

This bug prevents any graphical configuration of advanced keyboard layout settings, such as changing the shortcut key to switch between input languages (e.g., from Alt+Shift to something else). I was able to work around the issue by using gsettings in the terminal, but the GUI panel remains broken.

Steps to reproduce

Steps to Reproduce:

Open System Settings.
Navigate to the Keyboard section.
Click on the Layouts tab.
Click the Options... button.
The settings window immediately crashes.

(This can also be reproduced by running cinnamon-settings keyboard from a terminal and then clicking the "Options..." button.)

Expected behavior

Expected Behavior:

The "Keyboard Layout Options" window should open successfully, allowing for the configuration of advanced layout settings.

Actual Behavior:

The "Keyboard" settings window closes instantly. A Segmentation fault (core dumped) error is reported in the terminal.

Error Log:

The following output was captured when running cinnamon-settings keyboard from the terminal:

/usr/share/cinnamon/cinnamon-settings/cinnamon-settings.py:458: DeprecationWarning: Gtk.Window.set_wmclass is deprecated
self.window.set_wmclass(wm_class, wm_class)
Loading Keyboard module
(cinnamon-settings.py:32306): Gtk-CRITICAL **: 21:21:30.873: gtk_widget_get_toplevel: assertion 'GTK_IS_WIDGET (widget)' failed
Segmentation fault (core dumped)

Additional information

System Information:

Operating System: Linux Mint 22.1
Desktop Environment: Cinnamon
Cinnamon Version: (Cinnamon 6.4.8)

Thank you for your hard work on this fantastic desktop environment.

Start with cinnamon-settings keyboard and reproduce the crash by opening Layouts and clicking Options.... Trace the Keyboard settings entry point in /usr/share/cinnamon/cinnamon-settings/cinnamon-settings.py and investigate the reported gtk_widget_get_toplevel assertion. Done means the Keyboard Layout Options window opens without a segmentation fault.