PR feedback: Add exception handler around macro execution, add a mess…

…age about what is going on when list_schemas fails

core/dbt/adapters/base/impl.py

@@ -961,11 +961,12 @@ def execute_macro(
 
         macro_function = MacroGenerator(macro, macro_context)
 
-        try:
-            result = macro_function(**kwargs)
-        finally:
-            if release:
-                self.release_connection()
+        with self.connections.exception_handler(f'macro {macro_name}'):
+            try:
+                result = macro_function(**kwargs)
+            finally:
+                if release:
+                    self.release_connection()
         return result
 
     @classmethod

core/dbt/task/runnable.py

@@ -418,6 +418,7 @@ def list_schemas(db: str) -> List[Tuple[str, str]]:
                 ]
 
         def create_schema(db: str, schema: str) -> None:
+            assert False
             with adapter.connection_named(f'create_{db}_{schema}'):
                 adapter.create_schema(db, schema)
 

plugins/snowflake/dbt/adapters/snowflake/impl.py

@@ -8,7 +8,7 @@
 from dbt.adapters.snowflake import SnowflakeRelation
 from dbt.adapters.snowflake import SnowflakeColumn
 from dbt.contracts.graph.manifest import Manifest
-from dbt.exceptions import RuntimeException
+from dbt.exceptions import RuntimeException, DatabaseException
 from dbt.utils import filter_null_values
 
 
@@ -84,10 +84,17 @@ def post_model_hook(
             self._use_warehouse(context)
 
     def list_schemas(self, database: str) -> List[str]:
-        results = self.execute_macro(
-            LIST_SCHEMAS_MACRO_NAME,
-            kwargs={'database': database}
-        )
+        try:
+            results = self.execute_macro(
+                LIST_SCHEMAS_MACRO_NAME,
+                kwargs={'database': database}
+            )
+        except DatabaseException as exc:
+            msg = (
+                f'Database error while listing schemas in database '
+                f'"{database}"\n{exc}'
+            )
+            raise RuntimeException(msg)
         # this uses 'show terse schemas in database', and the column name we
         # want is 'name'