%pip install GitPython==3.1.11
Requirement already satisfied: GitPython==3.1.11 in /usr/local/python3.7/lib/python3.7/site-packages (3.1.11)
Requirement already satisfied: gitdb<5,>=4.0.1 in /usr/local/python3.7/lib/python3.7/site-packages (from GitPython==3.1.11) (4.0.5)
Requirement already satisfied: smmap<4,>=3.0.1 in /usr/local/python3.7/lib/python3.7/site-packages (from gitdb<5,>=4.0.1->GitPython==3.1.11) (3.0.4)
%cd $(mktemp -d)  
%git init .     
Initialized empty Git repository in /tmp/tmp.JXLEk4zfdj/.git/
%touch foo 
%git add foo                  
%git update-index --skip-worktree foo
%python3 -c '                        
import git           
with git.Repo(".", search_parent_directories=True) as repo:
 print(*repo.index.iter_blobs())
'
Traceback (most recent call last):
  File "<string>", line 4, in <module>
  File "/usr/local/python3.7/lib/python3.7/site-packages/git/index/base.py", line 441, in iter_blobs
    for entry in self.entries.values():
  File "/usr/local/python3.7/lib/python3.7/site-packages/gitdb/util.py", line 253, in __getattr__
    self._set_cache_(attr)
  File "/usr/local/python3.7/lib/python3.7/site-packages/git/index/base.py", line 128, in _set_cache_
    self._deserialize(stream)
  File "/usr/local/python3.7/lib/python3.7/site-packages/git/index/base.py", line 157, in _deserialize
    self.version, self.entries, self._extension_data, _conten_sha = read_cache(stream)
  File "/usr/local/python3.7/lib/python3.7/site-packages/git/index/fun.py", line 185, in read_cache
    version, num_entries = read_header(stream)
  File "/usr/local/python3.7/lib/python3.7/site-packages/git/index/fun.py", line 165, in read_header
    assert version in (1, 2)
AssertionError