Attached is a patch which allows the use of separate contexts.  For example

    try:
        ctx = multiprocessing.get_context('forkserver')
    except ValueError:
        ctx = multiprocessing.get_context('spawn')

    q = ctx.Queue()
    p = ctx.Process(target=foo, args=(q,))
    p.start()
    ...

Also, get_start_method(allow_none=True) will return None if the start method has not yet been fixed.