Slightly better error message for an edge case (#3442)

conftest.py

@@ -227,6 +227,11 @@ def pytest_pycollect_makeitem(collector, name, obj):
 
     if collector.istestclass(obj, name):
 
+        if obj is None:
+            message = f"""{collector.nodeid} is not properly collected.
+            You may have forgotten to return a value in a decorator like @features"""
+            raise ValueError(message)
+
         manifest = load_manifests()
 
         nodeid = f"{collector.nodeid}::{name}"
@@ -235,7 +240,10 @@ def pytest_pycollect_makeitem(collector, name, obj):
             declaration = manifest[nodeid]
             logger.info(f"Manifest declaration found for {nodeid}: {declaration}")
 
-            released(**declaration)(obj)
+            try:
+                released(**declaration)(obj)
+            except Exception as e:
+                raise ValueError(f"Unexpected error for {nodeid}.") from e
 
 
 def pytest_collection_modifyitems(session, config, items: list[pytest.Item]):