Re: [gentoo-user] Re: can fix preserved-rebuild ...

[Alan McKinnon <alan.mckinnon@gmail.com>]

On Saturday 06 June 2009 18:23:26 walt wrote:
> William Kenworthy wrote:
> > After each update, these appear, and for libusb, the number slowly
> > increases (up to 185 now).  so far I have done the suggested "emerge
> > @preserved-rebuild", plus tried rebuilding every package mentioned but
> > after building, there is no change ...
> >
> > !!! existing preserved libs:
> >>>> package: dev-libs/libusb-0.1.12-r5
> >
> >   *  - /lib/libusb.so
> >   *      used by /lib/udev/check-mtp-device (media-libs/libgphoto2-2.4.3)
> >   *      used by /usr/bin/dfutool (net-wireless/bluez-utils-3.36)
> >   *      used by /usr/bin/evolution (mail-client/evolution-2.26.2)
> >   *      used by 185 other files
> >
> >>>> package: x11-libs/libXaw-1.0.5
> >
> >   *  - /usr/lib/libXaw.so.8
> >   *  - /usr/lib/libXaw8.so
> >   *  - /usr/lib/libXaw8.so.8
> >   *  - /usr/lib/libXaw8.so.8.0.0
> >   *      used by /usr/bin/xgpsspeed (sci-geosciences/gpsd-2.38)
> > Use emerge @preserved-rebuild to rebuild packages using these libraries
> > rattus ~ #
>
> Are you using an unstable version of gentoo, e.g. ~x86 or ~amd64?  The
> only reason I know of for 'preserving' an old version is if there is also
> a newer one, i.e. libusb-1.0.1, which is a ~ version.
>
> On my ~amd64 machine I had both libusb-0.1.12-r5 and libusb-1.0.1.
> I just deleted the 0.1.12 and revdep-rebuild found and rebuilt usbutils,
> hal, and sane-backends with no problems, so there seems to be no reason
> to have the old version unless you perhaps have the new version masked
> on your machine for some reason?

Your assessment of the problem is incorrect. preserved-rebuild happens when 
you upgrade a package which other packages link to and causes brokenness. When 
the "used by" package is rebuilt, there is no need for the old live version to 
be kept (it's only consumers no longer do so) so it is unmerged.

Think of it this way:
revdep-rebuild finds broken packages after the fact when they are already 
broken.
preserved-rebuild detects those problems before they occur and takes measure 
to keep the system working meanwhile.

You will notice that after running "emerge @preserved-rebuild", revdep-rebuild 
almost invariably returns null results.

As for the OP, I can only guess what might be causing this. Let's start with 
obvious stuff:

1. Is portage the latest version for your arch?
2. What does revdep-rebuild return?
3. What is your arch, and is it a mixture of stable and ~?


-- 
alan dot mckinnon at gmail dot com