More tweakies ...

So, forget I even thought about dealing with the `MetadataError` here. I can't
collect "errors" here because `_get_dataset_metadata` actually internally
traps any "real" metadata error and returns a `None` value already. To collect
a list of keyspace errors I'd need to change `_get_dataset_metadata`, and I'm
not going to do that here.

The only `MetadataError` that can get through here is actually a bad keyname,
and we've already done that validation so we really don't need to worry about
it.

I'd like to revise this separately because I've realized that while I allow
`filter` to reference the weird non-alphanumeric key paths in `metalog`, I
didn't do that for the `metadata` parameter... and that'll affect the
`_get_dataset_metadata` as well because it independently validates the key
paths and wouldn't know about that exception. (Ugh.) Not here. I did however
add a test case showing that a keyspace conflict error results in a `None`
value.

lib/pbench/server/api/resources/datasets_list.py

@@ -382,22 +382,18 @@ def datasets(self, request: Request, json: JSONOBJECT, query: Query) -> JSONOBJE
         keys = json.get("metadata")
 
         response = []
-        errors = []
         for dataset in datasets:
             d = {
                 "name": dataset.name,
                 "resource_id": dataset.resource_id,
             }
             try:
                 d["metadata"] = self._get_dataset_metadata(dataset, keys)
-            except MetadataError as e:
-                errors.append(str(e))
+            except MetadataError:
                 d["metadata"] = None
             response.append(d)
 
         paginated_result["results"] = response
-        if errors:
-            paginated_result["errors"] = errors
         return paginated_result
 
     def _get(

lib/pbench/test/unit/server/test_datasets_list.py

@@ -345,6 +345,43 @@ def test_get_bad_keys(self, query_as):
             )
         }
 
+    def test_get_get_errors(self, server_config, query_as):
+        """Test case reporting key errors
+
+        Args:
+            query_as: Query helper fixture
+        """
+        fio_1 = Dataset.query(name="fio_1")
+        fio_2 = Dataset.query(name="fio_2")
+        Metadata.setvalue(dataset=fio_1, key="global.test", value="ABC")
+        Metadata.setvalue(dataset=fio_2, key="global.test.foo", value="ABC")
+        response = query_as(
+            {"metadata": "global.test.foo"},
+            "drb",
+            HTTPStatus.OK,
+        )
+        assert response.json == {
+            "next_url": "",
+            "results": [
+                {
+                    "metadata": {"global.test.foo": None},
+                    "name": "drb",
+                    "resource_id": "random_md5_string1",
+                },
+                {
+                    "metadata": {"global.test.foo": None},
+                    "name": "fio_1",
+                    "resource_id": "random_md5_string3",
+                },
+                {
+                    "metadata": {"global.test.foo": "ABC"},
+                    "name": "fio_2",
+                    "resource_id": "random_md5_string4",
+                },
+            ],
+            "total": 3,
+        }
+
     def test_get_unknown_keys(self, query_as):
         """Test case requesting non-existent query parameter keys.