Earmarks are broken
Tested on 3.36.0 and master.
Steps to reproduce:
Use keyboard only
- Navigate to any empty cell
Ctrl-1(can be any digit)
Ctrl-1 at step 5 doesn't make any visible changes.
- Click with right button on a selected cell to show earmarks popover
- Click with left button to hide the popover
Ctrl-1 at step 5 doesn't make any visible changes but also following is printed in a terminal
(gnome-sudoku:62063): Gtk-CRITICAL **: 17:08:01.307: gtk_toggle_button_set_active: assertion 'GTK_IS_TOGGLE_BUTTON (toggle_button)' failed