Comment 2 for bug 1531880

Similar problem:

2016-06-15 13:37:43,762 - util.py[WARNING]: failed of stage init
failed run of stage init
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Traceback (most recent call last):
  File "/usr/bin/cloud-init", line 520, in status_wrapper
    ret = functor(name, args)
  File "/usr/bin/cloud-init", line 250, in main_init
    init.fetch(existing=existing)
  File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 322, in fetch
    return self._get_data_source(existing=existing)
  File "/usr/lib/python3/dist-packages/cloudinit/stages.py", line 241, in _get_data_source
    util.del_file(self.paths.instance_link)
  File "/usr/lib/python3/dist-packages/cloudinit/util.py", line 1567, in del_file
    raise e
  File "/usr/lib/python3/dist-packages/cloudinit/util.py", line 1564, in del_file
    os.unlink(path)
IsADirectoryError: [Errno 21] Is a directory: '/var/lib/cloud/instance'
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