fix(ci): add warnings when MQ pull request body or metadata is missing (#985)

Log warnings instead of silently returning None when the merge queue
pull request has no body or no Mergify metadata in fenced blocks.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Author: sileht

mergify_cli/ci/queue/metadata.py

@@ -2,6 +2,7 @@
 
 import typing
 
+import click
 import yaml
 
 from mergify_cli import utils
@@ -54,8 +55,20 @@ def extract_from_event(ev: dict[str, typing.Any]) -> MergeQueueMetadata | None:
         return None
     if not title.startswith("merge queue: "):
         return None
-    body = pr.get("body") or ""
-    return _yaml_docs_from_fenced_blocks(body)
+    body = pr.get("body")
+    if not body:
+        click.echo(
+            "WARNING: MQ pull request without body, skipping metadata extraction",
+            err=True,
+        )
+        return None
+    ref = _yaml_docs_from_fenced_blocks(body)
+    if ref is None:
+        click.echo(
+            "WARNING: MQ pull request body without Mergify metadata, skipping metadata extraction",
+            err=True,
+        )
+    return ref
 
 
 def detect() -> MergeQueueMetadata | None: