Patch by Davin Potts and Camilla Montonen.
If the ``freeze_support()`` line is omitted then trying to run the frozen
executable will raise :exc:`RuntimeError`.
- If the module is being run normally by the Python interpreter then
- :func:`freeze_support` has no effect.
+ Calling ``freeze_support()`` has no effect when invoked on any operating
+ system other than Windows. In addition, if the module is being run
+ normally by the Python interpreter on Windows (the program has not been
+ frozen), then ``freeze_support()`` has no effect.
.. function:: get_all_start_methods()