Starting a title-less application (e.g., the test case from bug 601228 produces)

    JS ERROR: !!!   Exception was: Error: Argument 'text' (type utf8) may not be null
    JS ERROR: !!!     lineNumber = '0'
    JS ERROR: !!!     fileName = 'gjs_throw'
    JS ERROR: !!!     message = 'Argument 'text' (type utf8) may not be null'
    JS ERROR: !!!     stack = 'Error("Argument 'text' (type utf8) may not be null")@:0
("Argument 'text' (type utf8) may not be null")@gjs_throw:0
@:0
([object _private_Shell_WindowTracker],[object _private_GLib_ParamSpec])@/home/otaylor/gnome-shell/source/gnome-shell/js/ui/panel.js:156
([object _private_Shell_WindowTracker],[object _private_GLib_ParamSpec])@/home/otaylor/gnome-shell/install/share/gjs-1.0/lang.js:110
Error("Chained exception")@:0
("Chained exception")@gjs_throw:0