On Tue, 11 Dec 2012 07:36:10 -0600, Bruce Hill wrote:

> After using Gentoo for close to two years, the only time/place I've
> ever even seen @preserved-rebuild is in this thread. Yet you say,
> "Portage will warn you when the set is [it] non-empty, telling you to
> run emerge @preserved-rebuild."
>
> How will portage do this?

I've just got this after an emerge -u @world

!!! existing preserved libs:
>>> package: dev-libs/icu-50.1-r2
 *  - /usr/lib64/libicui18n.so.49
 *  - /usr/lib64/libicui18n.so.49.1.2
 *  - /usr/lib64/libicuio.so.49
 *  - /usr/lib64/libicuio.so.49.1.2
 *      used by /usr/sbin/cgdisk (sys-apps/gptfdisk-0.8.5)
 *      used by /usr/sbin/gdisk (sys-apps/gptfdisk-0.8.5)
 *      used by /usr/sbin/sgdisk (sys-apps/gptfdisk-0.8.5)
 *  - /usr/lib64/libicuuc.so.49
 *  - /usr/lib64/libicuuc.so.49.1.2
 *      used by /usr/sbin/cgdisk (sys-apps/gptfdisk-0.8.5)
 *      used by /usr/sbin/gdisk (sys-apps/gptfdisk-0.8.5)
 *      used by /usr/sbin/sgdisk (sys-apps/gptfdisk-0.8.5)
 *  - /usr/lib64/libicudata.so.49
 *  - /usr/lib64/libicudata.so.49.1.2
Use emerge @preserved-rebuild to rebuild packages using these libraries
 * After world updates, it is important to remove obsolete packages with
 * emerge --depclean. Refer to `man emerge` for more information.

You won't see that because the subsequent programs run by your alias will
scroll it out of view. The important point is that although the library
update could have broken gptfdisk, it didn't because portage is holing
onto the old library until I have run emerge @preserved-rebuild. Contrast
this with the previous approach of letting emerge break important
software and relying on revdep-rebuild to get it working again.


--
Neil Bothwick

All things being equal, fat people use more soap.