old_contents: import pytest
  import rostest.util as u
  from rostest.util import SSH
  
  
  @pytest.fixture(scope="module")
  def qemu(request):
      q = u.run_qemu(request, run_args=['--append', 'rancher.state.directory=ros_subdir'])
      u.flush_out(q.stdout)
      return q
  
  
  def test_system_docker_survives_custom_docker_install(qemu):
      SSH(qemu).check_call('bash', '-c', '''
          set -x -e
          mkdir x
          sudo mount $(ros dev LABEL=RANCHER_STATE) x
          [ -d x/ros_subdir/home/rancher ]
      '''.strip())
  
new_contents: import pytest
  import rostest.util as u
  from rostest.util import SSH
  
  
  @pytest.fixture(scope="module")
  def qemu(request):
      q = u.run_qemu(request, run_args=['--append', 'rancher.state.directory=ros_subdir'])
      u.flush_out(q.stdout)
      return q
  
  
  def test_system_docker_survives_custom_docker_install(qemu):
      SSH(qemu).check_call('bash', '-c', '''
          set -x -e
          mkdir x
          sudo mount $(sudo ros dev LABEL=RANCHER_STATE) x
          [ -d x/ros_subdir/home/rancher ]
      '''.strip())
  
subject: fix the testcase: add `sudo` to `ros dev` command