salt-master error with gitfs

[ERROR   ] Exception Require 20 byte binary sha, got '\xe6\x90', len = 2 occurred in file server update
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/salt/daemons/masterapi.py", line 270, in fileserver_update
    fileserver.update()
  File "/usr/lib/python2.7/dist-packages/salt/fileserver/__init__.py", line 453, in update
    self.servers[fstr]()
  File "/usr/lib/python2.7/dist-packages/salt/fileserver/gitfs.py", line 124, in update
    gitfs.update()
  File "/usr/lib/python2.7/dist-packages/salt/utils/gitfs.py", line 2218, in update
    self.find_file
  File "/usr/lib/python2.7/dist-packages/salt/fileserver/__init__.py", line 240, in reap_fileserver_cache_dir
    ret = find_func(filename, saltenv=saltenv)
  File "/usr/lib/python2.7/dist-packages/salt/utils/gitfs.py", line 2577, in find_file
    blob, blob_hexsha = repo.find_file(repo_path, tgt_env)
  File "/usr/lib/python2.7/dist-packages/salt/utils/gitfs.py", line 862, in find_file
    file_blob = tree / path
  File "/usr/lib/python2.7/dist-packages/git/objects/tree.py", line 172, in __div__
    item = tree[token]
  File "/usr/lib/python2.7/dist-packages/git/objects/tree.py", line 237, in __getitem__
    return self.__div__(item)
  File "/usr/lib/python2.7/dist-packages/git/objects/tree.py", line 188, in __div__
    return self._map_id_to_type[info[1] >> 12](self.repo, info[0], info[1], join_path(self.path, info[2]))
  File "/usr/lib/python2.7/dist-packages/git/objects/tree.py", line 133, in __init__
    super(Tree, self).__init__(repo, binsha, mode, path)
  File "/usr/lib/python2.7/dist-packages/git/objects/base.py", line 142, in __init__
    super(IndexObject, self).__init__(repo, binsha)
  File "/usr/lib/python2.7/dist-packages/git/objects/base.py", line 39, in __init__
    assert len(binsha) == 20, "Require 20 byte binary sha, got %r, len = %i" % (binsha, len(binsha))
AssertionError: Require 20 byte binary sha, got '\xe6\x90', len = 2