commit - a214d0e77727fa17f3384d4e8045f8f1749879cb
commit + a73668185f494dafd7230f3c7b0977bb47f7c46c
blob - 1b8357efd1d13f66bb8c4c5cceaf28b7b27788ed
blob + f2beaa8d7aefad7fdc91dbbd88c7c1acd22d33b1
--- swh/loader/git/loader.py
+++ swh/loader/git/loader.py
@@ -1326,6 +1326,8 @@ class GitLoader(BaseGitLoader):
                 if not branch:
                     unknown_objects[ref_name] = target
 
+            logger.debug(f"have {len(unknown_objects)} unknown objects")
+            logger.debug(f"have {len(self.base_snapshots)} base snaps")
             if unknown_objects and self.base_snapshots:
                 # The remote has sent us a partial packfile. It will have skipped
                 # objects that it knows are ancestors of the heads we have sent as
@@ -1335,6 +1337,9 @@ class GitLoader(BaseGitLoader):
                 refs_for_target = collections.defaultdict(list)
                 for ref_name, target in unknown_objects.items():
                     refs_for_target[target].append(ref_name)
+                    logger.debug(
+                        f"target {hashutil.hash_to_hex(target)!r} has ref {ref_name!r}"
+                    )
 
                 targets_unknown = set(refs_for_target)