add logging messages

jupyter_server/extension/application.py

@@ -318,7 +318,17 @@ def launch_instance(cls, argv=None, **kwargs):
         else:
             args = []
         # Get a jupyter server instance.
-        serverapp = cls.initialize_server(argv=args, load_other_extensions=cls.load_other_extensions)
+        serverapp = cls.initialize_server(
+            argv=args, 
+            load_other_extensions=cls.load_other_extensions
+        )
+        # Log if extension is blocking other extensions from loading.
+        if cls.load_other_extensions:
+            serverapp.log.info(
+                "{ext_name} is running without loading "
+                "other extensions.".format(ext_name=cls.extension_name)
+            )
+
         extension = cls._prepare_launch(serverapp, argv=args, **kwargs)
         # Start the ioloop.
         extension.start_server()

jupyter_server/serverapp.py

@@ -1415,6 +1415,8 @@ def init_server_extensions(self):
                     func = getattr(mod, 'load_jupyter_server_extension', None)
                     if func is not None:
                         func(self)
+                    # Add debug log for loaded extensions.
+                    self.log.debug("%s is enabled and loaded." % modulename)
                 except Exception:
                     if self.reraise_server_extension_failures:
                         raise