if e.errno in (errno.ENOENT, errno.ESTALE):

                      # likely racing with another rmtree

                      # if the dir doesn't exist, we're done

                      return

                  raise

              try:

                  # reset and retry

                  os.chdir(cwd)

                  continue

              break

      finally:

              raise

      """Remove all contents of CWD"""

      # This implementation avoids forming long paths and recursion. Otherwise

      # we will have errors with very deep directory trees.

      # As we descend into the tree, we append a new entry to dirstack

      # When we ascend back up after removal, we pop them off

      while True:

          # if cwd has no subdirs, walk back up until we find some

          while not dirs and dirstack:

              empty_dir = dirs.pop()

              try:

                  os.rmdir(empty_dir)

                  # If this happens, either something else is writing to the dir,

                  # or there is a bug in our code.

                  # For now, we ignore this and proceed, but we'll still fail at

                  # the top level rmdir

                  pass

          if not dirs:

                  # we'll ignore this and continue

                  # since subdir doesn't exist, we'll pop it off and forget about it

                  dirs.pop()

                  continue  # with dirstack unchanged

              raise

          dirstack.append(dirs)

      """Unlink all files in cwd and return list of subdirs"""

      dirs = []

      try:

          fdirs = os.listdir('.')

      except OSError as e:

          if e.errno in (errno.ENOENT, errno.ESTALE):

              return dirs

          raise

      for fn in fdirs:

          isdir.return_value = True

          getcwd.return_value = 'cwd'

          path = '/mnt/folder'

          chdir.assert_called_with('cwd')

          rmdir.assert_called_once_with(path)

      @patch('koji.util._rmtree')

      def test_rmtree_internal_empty(self, stripcwd, rmdir, chdir):

          dev = 'dev'

          stripcwd.return_value = []

          rmdir.assert_not_called()

          chdir.assert_not_called()

      def test_rmtree_internal_dirs(self, stripcwd, rmdir, chdir):

          dev = 'dev'

          stripcwd.side_effect = (['a', 'b'], [], [])

          rmdir.assert_has_calls([call('b'), call('a')])

          chdir.assert_has_calls([call('b'), call('..'), call('a'), call('..')])

          dev = 'dev'

          stripcwd.side_effect = (['a', 'b'], [], [])

          rmdir.side_effect = OSError()

          # don't fail on anything

          rmdir.assert_has_calls([call('b'), call('a')])

          chdir.assert_has_calls([call('b'), call('..'), call('a'), call('..')])

          # simple empty directory

          dev = 'dev'

          listdir.return_value = []

          listdir.assert_called_once_with('.')

          unlink.assert_not_called()

          st.st_mode = 'mode'

          lstat.return_value = st

          isdir.side_effect = [True, False]

          listdir.assert_called_once_with('.')

          unlink.assert_called_once_with('b')

          st2.st_mode = 'mode'

          lstat.side_effect = [st1, st2]

          isdir.side_effect = [True, False]

          listdir.assert_called_once_with('.')

          unlink.assert_not_called()

          lstat.return_value = st

          isdir.side_effect = [True, False]

          unlink.side_effect = OSError()

          listdir.assert_called_once_with('.')

          unlink.assert_called_once_with('b')

          dev = 'dev'

          listdir.return_value = ['will-not-exist.txt']

          lstat.side_effect = OSError(errno.ENOENT, 'No such file or directory')

          listdir.assert_called_once_with('.')

          lstat.assert_called_once_with('will-not-exist.txt')