Doing a world upgrade gives me:

root@kushiel / # emerge -uDvatN world

These are the packages that would be merged, in reverse order:

Calculating dependencies... done!

emerge: there are no ebuilds built with USE flags to satisfy "sys-
apps/pciutils[-zlib]".
!!! One of the following packages is required to complete your request:
- sys-apps/pciutils-3.1.7::gentoo (Change USE: -zlib)
(dependency required by "sys-fs/udev-171-r5[hwdb]" [ebuild])
(dependency required by "sys-fs/lvm2-2.02.88" [installed])
(dependency required by "sys-fs/udisks-1.0.4-r1" [installed])
(dependency required by "kde-base/kdelibs-4.7.4[udisks]" [installed])
(dependency required by "kde-base/kdesu-4.7.4" [installed])
(dependency required by "kde-base/khelpcenter-4.7.4" [installed])


But setting -lib use flag then gives me:

Calculating dependencies... done!

emerge: there are no ebuilds built with USE flags to satisfy ">=app-
arch/libarchive-2.6.1[bzip2?,lzma?,zlib]".
!!! One of the following packages is required to complete your request:
- app-arch/libarchive-3.0.3::gentoo (Change USE: +zlib)
(dependency required by "kde-base/ark-4.7.4" [installed])
(dependency required by "kde-base/kdeutils-meta-4.7.4" [installed])
(dependency required by "kde-base/kde-meta-4.7.4" [installed])
(dependency required by "@selected" [set])
(dependency required by "@world" [argument])


Is no one else seeing this?  What's the resolution?

-- 
"I always pass on good advice. It's the only thing to do with it. It is never 
any use to oneself." - Oscar Wilde