Log the plugin errors too

src/plugin.py

@@ -80,6 +80,7 @@ class SafetyMetaclass(type):
                 if inspect.stack()[1][1] == inspect.getfile(f):
                     raise
                 elif SafetyMetaclass.core:
+                    log.error('Error in a plugin', exc_info=True)
                     SafetyMetaclass.core.information(traceback.format_exc())
                     return None
         return helper