Added test on mount crawl.

src/databricks/labs/ucx/hive_metastore/locations.py

@@ -7,6 +7,7 @@
 from functools import cached_property
 from typing import ClassVar, Optional
 from urllib.parse import urlparse
+from py4j.protocol import Py4JError
 
 from databricks.labs.blueprint.installation import Installation
 from databricks.labs.lsql import Row
@@ -320,8 +321,15 @@ def _deduplicate_mounts(mounts: list) -> list:
 
     def _crawl(self) -> Iterable[Mount]:
         mounts = []
-        for mount_point, source, _ in self._dbutils.fs.mounts():
-            mounts.append(Mount(mount_point, source))
+        try:
+            for mount_point, source, _ in self._dbutils.fs.mounts():
+                mounts.append(Mount(mount_point, source))
+        except Py4JError as error:
+            if "com.databricks.backend.daemon.dbutils.DBUtilsCore.mounts() is not whitelisted" in str(error):
+                logger.warning(
+                    "dbutils.fs.mounts() is not whitelisted. Skipping mount point discovery."
+                    "Please make sure you run the assessment workflow."
+                )
         return self._deduplicate_mounts(mounts)
 
     def _try_fetch(self) -> Iterable[Mount]: