old_contents: import os
  from subprocess import PIPE, Popen
  
  from todoman.cli import cli
  
  
  def test_main(tmpdir, runner):
      root = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..')
      env = os.environ.copy()
      env['PYTHONPATH'] = root
  
      cli_result = runner.invoke(cli, ['--version'])
  
      pipe = Popen(
          ['python', '-m', 'todoman', '--version'], stdout=PIPE, env=env
      )
      main_output = pipe.communicate()[0]
  
      assert cli_result.output == main_output.decode()
  
new_contents: import os
  import sys
  from subprocess import PIPE, Popen
  
  from todoman.cli import cli
  
  
  def test_main(tmpdir, runner):
      root = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..')
      env = os.environ.copy()
      env['PYTHONPATH'] = root
  
      cli_result = runner.invoke(cli, ['--version'])
  
      pipe = Popen(
          [sys.executable, '-m', 'todoman', '--version'], stdout=PIPE, env=env
      )
      main_output = pipe.communicate()[0]
  
      assert cli_result.output == main_output.decode()
  
subject: Test main with the CURRENT python (#148)