Quoting Didier Kryn (kryn@???):

> Sorry, Rick, but I don't understand how it is possible that, on
> one hand, it needs libudev to configure itself, and, on the other
> hand, it is able to generate its config file without it. Can you
> explain this paradox?

Not really, no.

My guess is that the udev developers thought 'It'd be excellent to
automatically supply to the starting Xorg binary the output of "Xorg
-configure" when /etc/X11/Xorg.conf doesn't exist, thereby making Xorg
automagically able to reconfigure itself every time it starts without
ever bothering to create Xorg.conf' -- and somehow made the library
call to libudev perform that shim operation. All I really know is that
I was suddenly being told that creating Xorg.conf was no longer
necessary if you were adequately happy with the autoconfiguration
occuring in its absence.

The fine point you might have missed is, in the absence of the libudev
support, Xorg doesn't _automatically_ create an Xorg.conf nor default in
its absence to using what would have been created by 'Xorg -configure >
/etc/X11/Xorg.conf' if you had do that.

In fact, the old-school method was/is so cautious that its default
output (./Xorg.conf.new) is specifically crafted so you would _not_
accidetnally overwrite a production Xorg.conf .

Anyway, I can testify that 'Xorg -configure' does indeed output a
conffile that's usually really good. I did that for long years, and the
same with XFree86 before that.