android2.2 源码获取错误：error.GitError: platform/cts rev-list

pos@ubuntu:~/a2t$ repo sync

Fetching projects: 100% (158/158), done. 
Traceback (most recent call last):
  File "/home/pos/a2t/.repo/repo/main.py", line 385, in <module>
    _Main(sys.argv[1:])
  File "/home/pos/a2t/.repo/repo/main.py", line 365, in _Main
    result = repo._Run(argv) or 0
  File "/home/pos/a2t/.repo/repo/main.py", line 137, in _Run
    result = cmd.Execute(copts, cargs)
  File "/home/pos/a2t/.repo/repo/subcmds/sync.py", line 466, in Execute
    project.Sync_LocalHalf(syncbuf)
  File "/home/pos/a2t/.repo/repo/project.py", line 1007, in Sync_LocalHalf
    lost = self._revlist(not_rev(revid), HEAD)
  File "/home/pos/a2t/.repo/repo/project.py", line 1785, in _revlist
    return self.work_git.rev_list(*a, **kw)
  File "/home/pos/a2t/.repo/repo/project.py", line 1930, in rev_list
    p.stderr))
error.GitError: platform/cts rev-list ('^df72a2789b1a594fb5154c4ae1fb204f4b26c8c0', 'HEAD', '--'): fatal: Not a git repository (or any of the parent directories): .git

出现上面的错误，由于之前下载的部分android源码，没有删除。