if the gateway does not exist, continue the janitor process

sqlmesh/core/snapshot/evaluator.py

@@ -528,12 +528,27 @@ def cleanup(
         target_snapshots = [
             t for t in target_snapshots if t.snapshot.is_model and not t.snapshot.is_symbolic
         ]
+        available_gateways = set(self.adapters.keys())
+        skipped = []
+        filtered_targets = []
+        for t in target_snapshots:
+            gw = t.snapshot.model_gateway
+            if gw and gw not in available_gateways:
+                skipped.append((t.snapshot.snapshot_id, gw))
+            else:
+                filtered_targets.append(t)
+        if skipped:
+            logger.warning(
+                "Skipping cleanup of %d snapshot(s) with unavailable gateway(s): %s",
+                len(skipped),
+                ", ".join(f"{sid} (gateway={gw})" for sid, gw in skipped),
+            )
         snapshots_to_dev_table_only = {
-            t.snapshot.snapshot_id: t.dev_table_only for t in target_snapshots
+            t.snapshot.snapshot_id: t.dev_table_only for t in filtered_targets
         }
         with self.concurrent_context():
             concurrent_apply_to_snapshots(
-                [t.snapshot for t in target_snapshots],
+                [t.snapshot for t in filtered_targets],
                 lambda s: self._cleanup_snapshot(
                     s,
                     snapshots_to_dev_table_only[s.snapshot_id],

tests/core/test_snapshot_evaluator.py

@@ -4503,6 +4503,41 @@ def test_multiple_engine_cleanup(snapshot: Snapshot, adapters, make_snapshot):
     )
 
 
+def test_cleanup_skips_unavailable_gateway(snapshot: Snapshot, adapters, make_snapshot):
+    engine_adapters = {"default": adapters[0]}
+    evaluator = SnapshotEvaluator(engine_adapters)
+
+    model_with_missing_gw = load_sql_based_model(
+        parse(  # type: ignore
+            """
+            MODEL (
+                name test_schema.test_model,
+                kind FULL,
+                gateway nonexistent_gateway,
+            );
+            SELECT a::int FROM tbl;
+            """
+        ),
+    )
+
+    snapshot_missing_gw = make_snapshot(model_with_missing_gw)
+    snapshot.categorize_as(SnapshotChangeCategory.BREAKING)
+    snapshot_missing_gw.categorize_as(SnapshotChangeCategory.BREAKING)
+
+    evaluator.create([snapshot], {}, DeployabilityIndex.all_deployable())
+
+    evaluator.cleanup(
+        [
+            SnapshotTableCleanupTask(snapshot=snapshot.table_info, dev_table_only=True),
+            SnapshotTableCleanupTask(snapshot=snapshot_missing_gw.table_info, dev_table_only=True),
+        ],
+    )
+
+    engine_adapters["default"].drop_table.assert_called_once_with(
+        f"sqlmesh__db.db__model__{snapshot.version}__dev", cascade=True
+    )
+
+
 def test_multi_engine_python_model_with_macros(adapters, make_snapshot):
     engine_adapters = {"default": adapters[0], "secondary": adapters[1]}
     evaluator = SnapshotEvaluator(engine_adapters)