fix: plugin widget import machinery

- lazy import client so plugin widgets can import BECWidgets which use
  it indirectly
- exclude classes originating from bec_widgets core from plugin
  discovery
- better errors

bec_widgets/cli/client_utils.py

@@ -14,18 +14,21 @@ from typing import TYPE_CHECKING, Literal, TypeAlias, cast
 
 from bec_lib.endpoints import MessageEndpoints
 from bec_lib.logger import bec_logger
-from bec_lib.utils.import_utils import lazy_import_from
+from bec_lib.utils.import_utils import lazy_import, lazy_import_from
 from rich.console import Console
 from rich.table import Table
 
-import bec_widgets.cli.client as client
 from bec_widgets.cli.rpc.rpc_base import RPCBase, RPCReference
 from bec_widgets.utils.serialization import register_serializer_extension
 
 if TYPE_CHECKING:  # pragma: no cover
     from bec_lib.messages import GUIRegistryStateMessage
+
+    import bec_widgets.cli.client as client
 else:
     GUIRegistryStateMessage = lazy_import_from("bec_lib.messages", "GUIRegistryStateMessage")
+    client = lazy_import("bec_widgets.cli.client")
+
 
 logger = bec_logger.logger
 

bec_widgets/utils/bec_plugin_helper.py

@@ -38,9 +38,11 @@ def _loaded_submodules_from_specs(
         try:
             submodule.__loader__.exec_module(submodule)
         except Exception as e:
-            logger.error(
-                f"Error loading plugin {submodule}: \n{''.join(traceback.format_exception(e))}"
-            )
+            exception_text = "".join(traceback.format_exception(e))
+            if "(most likely due to a circular import)" in exception_text:
+                logger.warning(f"Circular import encountered while loading {submodule}")
+            else:
+                logger.error(f"Error loading plugin {submodule}: \n{exception_text}")
         yield submodule
 
 
@@ -59,7 +61,8 @@ def _get_widgets_from_module(module: ModuleType) -> BECClassContainer:
         module,
         predicate=lambda item: inspect.isclass(item)
         and issubclass(item, BECWidget)
-        and item is not BECWidget,
+        and item is not BECWidget
+        and not item.__module__.startswith("bec_widgets"),
     )
     return BECClassContainer(
         BECClassInfo(name=k, module=module.__name__, file=module.__loader__.get_filename(), obj=v)