old_contents: #!/usr/bin/env python3
  
  import os
  import os.path
  import sys
  
  myself = os.getcwd()
  dir = os.path.dirname(__file__)
  if dir:
    myself += '/%s' % dir
  sys.path = [myself + '/../src'] + sys.path
  os.environ['PYTHONPATH'] = ':'.join(sys.path)
  
  import doctest
  import drake
  import drake.git
  import drake.python
  import drake.utils
  
  doctest.testmod(drake)
  doctest.testmod(drake.git)
  doctest.testmod(drake.python)
  doctest.testmod(drake.utils)
  
  assert os.system('src/drake/sched.py') == 0
  os.chdir('_build')
  assert os.system('./drake-build.py //check') == 0
  
new_contents: #!/usr/bin/env python3
  
  import os
  import os.path
  import sys
  
  myself = os.getcwd()
  dir = os.path.dirname(__file__)
  if dir:
    myself += '/%s' % dir
  sys.path = [myself + '/../src'] + sys.path
  os.environ['PYTHONPATH'] = ':'.join(sys.path)
  
  import doctest
  import drake
  import drake.git
  import drake.python
  import drake.utils
  
  assert(doctest.testmod(drake)[0] == 0)
  assert(doctest.testmod(drake.git)[0] == 0)
  assert(doctest.testmod(drake.python)[0] == 0)
  assert(doctest.testmod(drake.utils)[0] == 0)
  assert os.system('src/drake/sched.py') == 0
  os.chdir('_build')
  assert os.system('./drake-build.py //check') == 0
  
subject: Make the test suite fail if doctest fail.