Why we disable the USB link on platforms other than Linux?

[Calvin Liu <Calvin Liu Sun COM>]

Hi, there,

Here is a piece of code from gpilotd/gpilotd.c. If I'm correct, in line
971, g_assert_not_reached() will terminal the process on any platforms
other than Linux.
Why we have to do it?

        } if (dev->type == PILOT_DEVICE_USB_VISOR) {
#ifdef WITH_USB_VISOR
#ifdef linux
                /* We want to watch the /proc/bus/usb/devices file once
                 * per context, and then check all devices each time it
is
                 * woken up. */
                if (visor_timeout_id == -1) {
                        visor_timeout_id = g_timeout_add (2000,
visor_devices_timeout, context);
                }
#else /* linux*/
971:                g_assert_not_reached ();
#endif /* linux */
#endif /* WITH_USB_VISOR */
                dev->device_exists = FALSE;
        }

Thanks.
Calvin