new_contents: import os
  import shutil
  from subprocess import run, PIPE
  
  import pytest
  
  @pytest.mark.usefixtures('both_debug_modes', 'both_setsid_modes')
  def test_working_directories():
      """The child process must start in the working directory in which
      dumb-init was invoked, but dumb-init itself should not keep a
      reference to that."""
  
      # We need absolute path to dumb-init since we pass cwd=/tmp to get
      # predictable output - so we can't rely on dumb-init being found
      # in the "." directory.
      dumb_init = os.path.realpath(shutil.which('dumb-init'))
      proc = run((dumb_init,
                  'sh', '-c', 'readlink /proc/$PPID/cwd && readlink /proc/$$/cwd'),
                 cwd="/tmp", stdout=PIPE, stderr=PIPE)
  
      assert proc.returncode == 0
      assert proc.stdout == b'/\n/tmp\n'
  
subject: add test for chdir("/") behaviour