michael@0: var { Cc, Ci } = require("chrome");
michael@0: var { once } = require("sdk/system/events");
michael@0: 
michael@0: var observerService = Cc["@mozilla.org/observer-service;1"].getService(Ci.nsIObserverService);
michael@0: var observer = {
michael@0:   observe: function () {
michael@0:     debugger;
michael@0:   }
michael@0: };
michael@0: 
michael@0: once("sdk:loader:destroy", () => observerService.removeObserver(observer, "debuggerAttached"));
michael@0: 
michael@0: observerService.addObserver(observer, "debuggerAttached", false);