--- a/firefox-devel.rst	Mon Oct 14 13:08:49 2013 +0300
+++ b/firefox-devel.rst	Tue Oct 22 22:52:02 2013 +0300
@@ -95,6 +95,11 @@
   // This will send more detailed information about installation and update problems to the Error Console.
   user_pref("extensions.logging.enabled", true);
   user_pref("dom.report_all_js_exceptions", true);
+  // This adds a "Browser Debugger" entry to the "Web Developer" submenu of the "Tools" menu.
+  // The Browser Debugger can be used to debug the JavaScript code of extensions.
+  user_pref("devtools.debugger.remote-enabled", true);
+  // Detect deprecated code use.
+  user_pref("devtools.errorconsole.deprecation_warnings", true);
 
 See: