On 22/02/2014 23:15, Alan Mackenzie wrote:
> Hi, Gentoo.
>
> I've just tried an emerge -puND world, after a shockingly long interval.
> I got the error message:
>
> !!! Multiple package instances within a single package slot have been
> pulled
> !!! into the dependency graph, resulting in a slot conflict:
>
> , etc.
>
> To simplify the problem, I tried to emerge an individual package
> identified in that message, and tried emerge -p libpng. I got the same
> message, with this:
>
> ###############################################################################
> !!! Multiple package instances within a single package slot have been pulled
> !!! into the dependency graph, resulting in a slot conflict:
>
> media-libs/libpng:0
>
> (media-libs/libpng-1.5.17-r1::gentoo, installed) pulled in by
> media-libs/libpng:0/0= required by (x11-libs/cairo-1.12.14-r4::gentoo,
> installed)
> >=media-libs/libpng-1.4:0/0= required by
> (app-editors/emacs-24.3-r2::gentoo, installed)
> media-libs/libpng:0/0= required by (media-libs/libwebp-0.3.1::gentoo,
> installed)
> media-libs/libpng:0/0= required by
> (net-print/cups-filters-1.0.36-r1::gentoo, installed)
> media-libs/libpng:0/0= required by (kde-base/kdelibs-4.11.2-r1::gentoo,
> installed)
> media-libs/libpng:0/0= required by (dev-qt/qtgui-4.8.5-r1::gentoo,
> installed)
> media-libs/libpng:0/0= required by (app-text/poppler-0.24.3::gentoo,
> installed)
> (and 3 more with the same problems)
>
> (media-libs/libpng-1.6.8::gentoo, ebuild scheduled for merge) pulled in by
> (no parents that aren't satisfied by other packages in this slot)
> ###############################################################################
> Clearly, I'm trying to update libpng-1.5.17 to libpng-1.6.8. What does
> this portion of the message mean:
>
> media-libs/libpng:0/0=
> ^^^^^
>
> ? Is it somehow telling me that cairo and friends require the currently
> installed version, whatever that is? Where is this format documented? I
> couldn't find anything about it in the Gentoo handbook, and not in the
> emerge man page either.
>
> What do I have to do to get this thing emerged?
>
> Thanks!
>
You've hit the dreaded sub-slot (a new portage feature). It causes no
end of trouble as so few people know how it really works, but it's
intended to replace @preserved-rebuild by DoingItRite and finally make
revdep-rebuild obsolete.
It's documented in man 5 ebuild under these headings:
Atom Slots
Sub Slots
Atom Slot Operators
SLOT
libpng:0/0 is libpng SLOT 0 which has been around since EAPI1 and
SUBSLOT 0 which is new.
Take cairo which is one of your deps. In the ebuild:
RDEPEND="
media-libs/libpng:0=
"
eix libpng shows:
(0) 1.5.15 1.5.17-r1 (~)1.6.6(0/16) (~)1.6.7(0/16) 1.6.8(0/16)
(~)1.6.9(0/16)
That shows libpng-1.5.* have slot/subslot 0/0 and
libpng-1.6.* have slot/subslot 0/16
where presumably "16" is shorthand for "1.6" in the version
Now read those headings in the man page, you will find this gem:
"= Indicates that any slot value is acceptable. In addition, for
runtime dependencies, indicates that the package will break unless a
matching package with slot and sub-slot equal to the slot and
sub-slot of the best installed version at the time the package was
installed is available.
Examples:
dev-libs/icu:=
dev-lang/perl:=
dev-libs/glib:=
"
in other words, even though libpng-1.5.17-r1 and libpng-1.6.8 are in the
same SLOT, nevertheless cairo will break if you upgrade libpng that way.
Or expressed another way in language from before sub-slots, cairo will
stop working properly after the emerge world until you run
revdep-rebuild and fix and the borkage
The world update wants to upgrade libpng as a new stable version is
available but portage won't do it as it will break packages that use libpng.
All my hosts here are up to date so I can't reproduce your problem:
- is portage up to date runnign latest version in your tree? Update that
first (always a good idea anyway)
- are you sure that's an emerge failure and not just a convoluted info
message? Perhaps post the entire emerge output.
--
Alan McKinnon
[email protected]
