old_contents: # -*- coding: utf-8 -*-
  """
      Sphinx - Python documentation toolchain
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
      :copyright: 2007 by Georg Brandl.
      :license: Python license.
  """
  
  import sys
  
  if __name__ == '__main__':
  
      if sys.version_info[:3] < (2, 5, 1):
          print("""\
  Error: Sphinx needs to be executed with Python 2.5.1 or newer
  (If you run this from the Makefile, you can set the PYTHON variable
  to the path of an alternative interpreter executable, e.g.,
  ``make html PYTHON=python2.5``).
  """, file=sys.stderr)
          sys.exit(1)
  
      from sphinx import main
      sys.exit(main(sys.argv))
  
new_contents: # -*- coding: utf-8 -*-
  """
      Sphinx - Python documentation toolchain
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
      :copyright: 2007 by Georg Brandl.
      :license: Python license.
  """
  
  import sys
  
  if __name__ == '__main__':
  
      if not (2, 5, 1) <= sys.version_info[:3] < (3, 0, 0):
          sys.stderr.write("""\
  Error: Sphinx needs to be executed with Python 2.5.1 or newer (not 3.0 though).
  If you run this from the Makefile, you can set the PYTHON variable to the path
  of an alternative interpreter executable, e.g., ``make html PYTHON=python2.5``.)
  """)
          sys.exit(1)
  
      from sphinx import main
      sys.exit(main(sys.argv))
  
subject: Fix sphinx-build so that it runs with 2.x and 3.x but refuses to start with 3.x.