KeyError in _ensure_no_pending

[progval]

While on the latest master (e71ece5):

$ python3 examples/clone.py https://github.com/ZSYniming/danwangshimoluo-JdScripts
Enumerating objects: 6885, done.
Counting objects: 100% (998/998), done.
Compressing objects: 100% (310/310), done.
Total 6885 (delta 635), reused 997 (delta 634), pack-reused 5887
copied 6884 pack entries84/6885
Traceback (most recent call last):
  File "/home/dev/dulwich/examples/clone.py", line 32, in <module>
    porcelain.clone(args[1], target_path)
  File "/home/dev/dulwich/dulwich/porcelain.py", line 542, in clone
    return client.clone(
           ^^^^^^^^^^^^^
  File "/home/dev/dulwich/dulwich/client.py", line 738, in clone
    result = self.fetch(path, target, progress=progress, depth=depth)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/dev/dulwich/dulwich/client.py", line 828, in fetch
    commit()
  File "/home/dev/dulwich/dulwich/client.py", line 807, in commit
    target.object_store.add_thin_pack(f.read, None, progress=progress)
  File "/home/dev/dulwich/dulwich/object_store.py", line 932, in add_thin_pack
    return self._complete_pack(f, path, len(copier), indexer, progress=progress)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/dev/dulwich/dulwich/object_store.py", line 863, in _complete_pack
    for i, entry in enumerate(indexer):
  File "/home/dev/dulwich/dulwich/pack.py", line 1441, in _walk_all_chains
    yield from self._walk_ref_chains()
  File "/home/dev/dulwich/dulwich/pack.py", line 1468, in _walk_ref_chains
    self._ensure_no_pending()
  File "/home/dev/dulwich/dulwich/pack.py", line 1446, in _ensure_no_pending
    raise KeyError([sha_to_hex(s) for s in self._pending_ref])
KeyError: [b'f320f4e315e866165c67c1802083574089050b19', b'2f451452900231f4b99e22695e824bbaa226779d']

[jelmer]

This is expected, the repository has unresolved deltas.

C git fails as well:

% git clone https://github.com/ZSYniming/danwangshimoluo-JdScripts
Cloning into 'danwangshimoluo-JdScripts'...
remote: Enumerating objects: 6885, done.
remote: Counting objects: 100% (998/998), done.
remote: Compressing objects: 100% (310/310), done.
remote: Total 6885 (delta 635), reused 997 (delta 634), pack-reused 5887
Receiving objects: 100% (6885/6885), 8.69 MiB | 2.75 MiB/s, done.
Resolving deltas:  95% (4293/4498), completed with 0 local objects.
fatal: pack has 205 unresolved deltas
fatal: fetch-pack: invalid index-pack output

we could probably raise a different exception if you wanted to catch this specifically and distinguish it from other errors?

[progval]

Ah sorry, I didn't think of checking it worked with git clone.

we could probably raise a different exception if you wanted to catch this specifically and distinguish it from other errors?

That would be nice, thanks!