Handle exceptions when loading extensions

openflexure_microscope/common/flask_labthings/extensions.py

@@ -1,6 +1,7 @@
 import logging
 import collections
 import copy
+import traceback
 
 from importlib import util
 import sys
@@ -20,6 +21,7 @@ class BaseExtension:
 
     Handles binding route views and forms.
     """
+
     # TODO: Allow adding components to extensions
 
     def __init__(self, name: str, description="", version="0.0.0"):
@@ -113,19 +115,25 @@ def find_instances_in_module(module, class_to_find):
     return objs
 
 
-def find_extensions_in_file(extension_path: str, module_name="extensions"):
+def find_extensions_in_file(extension_path: str, module_name="extensions") -> list:
     logging.debug(f"Loading extensions from {extension_path}")
 
     spec = util.spec_from_file_location(module_name, extension_path)
     mod = util.module_from_spec(spec)
     sys.modules[spec.name] = mod
 
-    spec.loader.exec_module(mod)
-
-    if hasattr(mod, "__extensions__"):
-        return [getattr(mod, ext_name) for ext_name in mod.__extensions__]
+    try:
+        spec.loader.exec_module(mod)
+    except Exception as e:
+        logging.error(
+            f"Exception in extension path {extension_path}: \n{traceback.format_exc()}"
+        )
+        return []
     else:
-        return find_instances_in_module(mod, BaseExtension)
+        if hasattr(mod, "__extensions__"):
+            return [getattr(mod, ext_name) for ext_name in mod.__extensions__]
+        else:
+            return find_instances_in_module(mod, BaseExtension)
 
 
 def find_extensions(extension_dir: str, module_name="extensions"):