Ok, so apparently Cairo Dock's (new) notification area supports only the new systray spec, which is implemented by KDE and Ubuntu's indicators, but not by Gtk (which is what gCDEmu uses by default).
I guess running gCDEmu in Ubuntu indicator mode should do the trick for you; try running 'gcdemu --indicator' and see if it works? It requires AppIndicator3 or AppIndicator python bindings, so you might need to install a package that provides them...
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Will look into it.
Ok, so apparently Cairo Dock's (new) notification area supports only the new systray spec, which is implemented by KDE and Ubuntu's indicators, but not by Gtk (which is what gCDEmu uses by default).
I guess running gCDEmu in Ubuntu indicator mode should do the trick for you; try running 'gcdemu --indicator' and see if it works? It requires AppIndicator3 or AppIndicator python bindings, so you might need to install a package that provides them...