Re: [gentoo-user] Beta test Gentoo with mdev instead of udev; version 5 - failure :-(

["Canek Peláez Valdés" <caneko@gmail.com>]

On Tue, Mar 13, 2012 at 1:47 PM, Alan Mackenzie <acm@muc.de> wrote:
> Hello, Walter,
>
> On Tue, Mar 13, 2012 at 03:00:52PM -0400, Walter Dnes wrote:
>> On Tue, Mar 13, 2012 at 01:05:34PM +0000, Alan Mackenzie wrote
>
>> > I also did "2> {system,world}.err".  system.err was empty.  I've included
>> > world.err in the enclosed tarball.
>
>>   From your error listing, it looks like lvm2, kde, and gnome (including
>> the XFCE subset) require udev.  Ouch.
>
> :-)  This cannot be the case.  Otherwise somebody would have said.  Hmm.
> What we could do with is a "requires xdev", for x in (m u).  I've
> forgotten what that's called in portage.
>
> There are surely lots of packages marked "need udev" which don't really
> need it at all.  I mean, are there any programs which need precisely
> udev to work, as opposed to a populated /dev?
>
> I mean, what does udev give me that mdev won't?  That's not really a
> rhetorical question.  What potential benefits am I throwing away by
> converting to mdev?

From my desktop:

centurion ~ # equery depends udev
 * These packages depend on udev:
dev-libs/libatasmart-0.18 (>=sys-fs/udev-143)
dev-python/python-gudev-147.2 (>=sys-fs/udev-171[gudev])
                              (>=sys-fs/udev-147[extras])
gnome-base/gnome-settings-daemon-3.2.2-r1 (packagekit ? sys-fs/udev[gudev])
                                          (packagekit ? sys-fs/udev[extras])
                                          (udev ? sys-fs/udev[gudev])
                                          (udev ? sys-fs/udev[extras])
gnome-base/gvfs-1.10.1 (!prefix ? >=sys-fs/udev-164-r2)
                       (>=sys-fs/udev-171[gudev])
                       (>=sys-fs/udev-145[extras])
media-gfx/shotwell-0.11.6 (>=sys-fs/udev-171[gudev])
                          (>=sys-fs/udev-145[extras])
media-libs/libcanberra-0.28-r5 (udev ? >=sys-fs/udev-160)
media-libs/libgpod-0.8.0 (udev ? sys-fs/udev)
media-libs/mesa-7.11.2 (gbm ? sys-fs/udev)
media-sound/pulseaudio-1.1-r1 (udev ? >=sys-fs/udev-171[hwdb])
                              (udev ? >=sys-fs/udev-143[extras])
media-sound/rhythmbox-2.95 (>=sys-fs/udev-171[gudev])
                           (>=sys-fs/udev-145[extras])
media-video/cheese-3.2.2 (>=sys-fs/udev-171[gudev])
                         (>=sys-fs/udev-145-r1[extras])
net-im/empathy-3.2.2 (v4l ? sys-fs/udev[gudev])
                     (v4l ? sys-fs/udev[extras])
net-misc/networkmanager-0.9.2.0-r5 (>=sys-fs/udev-171[gudev])
                                   (>=sys-fs/udev-147[extras])
net-wireless/bluez-4.98-r2 (>=sys-fs/udev-169)
net-wireless/gnome-bluetooth-3.2.2 (sys-fs/udev)
sys-apps/systemd-43-r1 (>=sys-fs/udev-172)
sys-fs/lvm2-2.02.88 (>=sys-fs/udev-151-r4)
sys-fs/udisks-1.0.4-r1 (>=sys-fs/udev-171[gudev])
                       (>=sys-fs/udev-147[extras])
sys-kernel/dracut-017-r2 (>=sys-fs/udev-164)
sys-power/upower-0.9.15 (kernel_linux ? >=sys-fs/udev-171-r1[gudev])
                        (kernel_linux ? <sys-fs/udev-171-r1[extras])
virtual/dev-manager-0 (sys-fs/udev)
x11-base/xorg-server-1.11.2-r2 (udev ? >=sys-fs/udev-150)
x11-libs/cairo-1.10.2-r1 (drm ? >=sys-fs/udev-136)
x11-misc/colord-0.1.15 (udev ? sys-fs/udev[gudev])
                       (udev ? sys-fs/udev[extras])

I don't know exactly what packages actually *require* udev. What I can
say with some certainty is that more and more "maistream" packages
will require udev either directly or indirectly (by some dep).

You will lose those with mdev.

"Fringe" programs will not require udev, or it will be optional; but
the moment a "fringe" program reaches critical mass to become
"maistream", the probability of it needing udev (directly or
indirectly) will increase.

I'm willing to bet a beer on that prediction.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México