[bug] Fixes for plugin loading mechanism (#9826)

* Fix logic for registry mutex lock

* Handle potential errors during UsersConfig launch

* Remove debug statement

* Revert to_raise value

* Clear plugin errors on reload

* Better method of avoiding duplicates

src/backend/InvenTree/plugin/registry.py

@@ -88,7 +88,7 @@ class PluginsRegistry:
         self.plugin_modules: list[InvenTreePlugin] = []  # Holds all discovered plugins
         self.mixin_modules: dict[str, Any] = {}  # Holds all discovered mixins
 
-        self.errors = {}  # Holds discovering errors
+        self.errors = {}  # Holds errors discovered during loading
 
         self.loading_lock = Lock()  # Lock to prevent multiple loading at the same time
 
@@ -307,6 +307,7 @@ class PluginsRegistry:
         full_reload: bool = False,
         force_reload: bool = False,
         collect: bool = False,
+        clear_errors: bool = False,
         _internal: Optional[list] = None,
     ):
         """Reload the plugin registry.
@@ -317,6 +318,7 @@ class PluginsRegistry:
             full_reload (bool, optional): Reload everything - including plugin mechanism. Defaults to False.
             force_reload (bool, optional): Also reload base apps. Defaults to False.
             collect (bool, optional): Collect plugins before reloading. Defaults to False.
+            clear_errors (bool, optional): Clear any previous loading errors. Defaults to False.
             _internal (list, optional): Internal apps to reload (used for testing). Defaults to None
         """
         # Do not reload when currently loading
@@ -324,7 +326,15 @@ class PluginsRegistry:
             logger.debug('Skipping reload - plugin registry is currently loading')
             return
 
-        if self.loading_lock.acquire(blocking=False):
+        if not self.loading_lock.acquire(blocking=False):
+            logger.exception('Could not acquire lock for reload_plugins')
+            return
+
+        # Reset the loading error state
+        if clear_errors:
+            self.errors = {}
+
+        try:
             logger.info(
                 'Plugin Registry: Reloading plugins - Force: %s, Full: %s, Collect: %s',
                 force_reload,
@@ -343,10 +353,15 @@ class PluginsRegistry:
             self._load_plugins(full_reload=full_reload, _internal=_internal)
 
             self.update_plugin_hash()
-
-            self.loading_lock.release()
             logger.info('Plugin Registry: Loaded %s plugins', len(self.plugins))
 
+        except Exception as e:
+            logger.exception('Expected error during plugin reload: %s', e)
+
+        finally:
+            # Ensure the lock is released always
+            self.loading_lock.release()
+
     def plugin_dirs(self):
         """Construct a list of directories from where plugins can be loaded."""
         # Builtin plugins are *always* loaded

src/backend/InvenTree/plugin/serializers.py

@@ -213,6 +213,7 @@ class PluginReloadSerializer(serializers.Serializer):
             full_reload=self.validated_data.get('full_reload', False),
             force_reload=self.validated_data.get('force_reload', False),
             collect=self.validated_data.get('collect_plugins', False),
+            clear_errors=True,
         )
 
 

src/backend/InvenTree/users/apps.py

@@ -35,11 +35,15 @@ class UsersConfig(AppConfig):
                 rebuild_all_permissions()
             except (OperationalError, ProgrammingError):
                 pass
+            except Exception as e:
+                logger.exception('Failed to rebuild permissions: %s', e)
 
             try:
                 self.update_owners()
             except (OperationalError, ProgrammingError):
                 pass
+            except Exception as e:
+                logger.exception('Failed to update owners: %s', e)
 
     def update_owners(self):
         """Create an 'owner' object for each user and group instance."""