--prefix=/usr
when installing custom version you can restore them using:gnome-session
. If wingpanel is stopped/killed twice within a minute, it will stop automatically restarting, and you can gather logs:killall io.elementary.wingpanel
twice to stop the current WingPanelG_MESSAGES_DEBUG=all io.elementary.wingpanel
killall gala
DISPLAY=:0 gala --replace &
sudo apt install --reinstall gala
.