Normalise path to both packages and modules

shepherd/agent/plugin.py

@@ -171,7 +171,7 @@ def load_plugin(plugin_name, plugin_dir=None):
             mod = importlib.import_module(plugin_name)
         finally:
             sys.path = saved_syspath
-        modpath = getattr(mod, "__path__", mod.__file__)
+        modpath = getattr(mod, "__path__", [mod.__file__])[0]
         log.info(F"Loading custom plugin {plugin_name} from {modpath}")
 
     elif plugin_name in discover_installed_plugins():