При попытке установки или обновлении, выдает такое сообщения:

calculate home # emerge www-client/chromium

* IMPORTANT: 8 news items need reading for repository ‘gentoo’.
* Use eselect news to read news items.

Calculating dependencies… done!
[ebuild N ] media-libs/libvpx-1.0.0 USE=“mmx sse sse2 threads (-altivec) -debug -doc -postproc -sse3 -sse4_1 -ssse3 -static-libs”
[ebuild N ] app-accessibility/espeak-1.45.04 USE=“-portaudio -pulseaudio”
[ebuild N ] dev-libs/dotconf-1.3
[ebuild N ] app-accessibility/speech-dispatcher-0.7.1-r1 USE=“espeak -alsa -ao -flite -nas -pulseaudio -python”
[ebuild N ] media-libs/opus-1.0.1 USE=“-doc -static-libs”
[ebuild N ] dev-libs/protobuf-2.4.0a USE=“-emacs -examples -java -python -source -static-libs -vim-syntax”
[ebuild U ] dev-lang/v8-3.15.11.15 [3.13.7.5]
[ebuild N ] media-libs/harfbuzz-0.9.12 USE=“-static-libs”
[ebuild N ] sys-apps/kmod-12-r1 USE=“tools zlib -debug -doc -lzma -static-libs”
[uninstall ] sys-apps/module-init-tools-3.16-r2
[blocks b ] sys-apps/module-init-tools (“sys-apps/module-init-tools” is blocking sys-apps/kmod-12-r1)
[blocks b ] sys-apps/kmod (“sys-apps/kmod” is blocking sys-apps/module-init-tools-3.16-r2)
[ebuild U ] sys-fs/udev-197-r8 [171-r9] USE=“acl* kmod* openrc* -doc -gudev* -hwdb* -static-libs%”
[ebuild U ] virtual/udev-197-r1 [171] USE=“kmod%* -gudev* -hwdb*”
[ebuild N ] sys-fs/udev-init-scripts-23
[ebuild U ] www-client/chromium-25.0.1364.152 [23.0.1271.97] USE=“-cups* (-system-ffmpeg)” LINGUAS=“am* ar* bn* ca* cs* da* el* en_GB* es_LA* et* fa* fi* fil* gu* he* hi* hr* hu* id* ja* kn* ko* lt* lv* ml* mr* ms* nb* nl* sk* sl* sr* sv* sw* ta* te* th* tr* vi* zh_CN* zh_TW*”
[blocks B ] <sys-fs/lvm2-2.02.97-r1 (“<sys-fs/lvm2-2.02.97-r1” is blocking sys-fs/udev-197-r8)
[blocks B ] <sys-fs/udev-186 (“<sys-fs/udev-186” is blocking sys-fs/udev-init-scripts-23)

!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:

virtual/udev:0

(virtual/udev-171::gentoo, installed) pulled in by
virtual/udev[gudev] required by (net-misc/networkmanager-0.9.6.4::gentoo, installed)
virtual/udev[gudev] required by (net-misc/modemmanager-0.6.0.0::gentoo, installed)
virtual/udev[gudev,hwdb] required by (sys-fs/udisks-1.0.4-r2::gentoo, installed)
<virtual/udev-196 required by (sys-fs/lvm2-2.02.88::gentoo, installed)

(virtual/udev-197-r1::gentoo, ebuild scheduled for merge) pulled in by

=virtual/udev-197-r1 required by (sys-fs/udev-197-r8::gentoo, ebuild scheduled for merge)
=virtual/udev-197-r1 required by (media-libs/libgpod-0.8.2::gentoo, installed)
(and 15 more with the same problems)

sys-fs/udev:0

(sys-fs/udev-171-r9::gentoo, installed) pulled in by

=sys-fs/udev-171-r6[gudev] required by (sys-power/upower-0.9.18::gentoo, installed)
~sys-fs/udev-171[gudev?,hwdb?,introspection?,keymap?,selinux?] required by (virtual/udev-171::gentoo, installed)

(sys-fs/udev-197-r8::gentoo, ebuild scheduled for merge) pulled in by

=sys-fs/udev-197-r8[gudev?,hwdb?,introspection?,keymap?,kmod?,selinux?,static-libs?] required by (virtual/udev-197-r1::gentoo, ebuild scheduled for merge)

It may be possible to solve this problem by using package.mask to
prevent one of those packages from being selected. However, it is also
possible that conflicting dependencies exist such that they are
impossible to satisfy simultaneously. If such a conflict exists in
the dependencies of two different packages, then those packages can
not be installed simultaneously.

For more information, see MASKED PACKAGES section in the emerge man
page or refer to the Gentoo Handbook.

!!! The following installed packages are masked:

  • net-wireless/rtl8192su-firmware-2.6.0001.0320.2009::gentoo (masked by: package.mask)
    /usr/portage/profiles/package.mask:
    # Rick Farina zerochaos@gentoo.org (10 Feb 2013)
    # This firmware has been replaced by rtlwifi/*
    # which is already in the linux-firmware package.
    # Removal in 30 days

  • net-wireless/prism54-firmware-2.13::gentoo (masked by: package.mask)
    /usr/portage/profiles/package.mask:
    # Samuli Suominen ssuominen@gentoo.org (10 Feb 2013)
    # There is no license file available for prism54-firmware
    # since it’s been extracted from windows binary blob
    # drivers. And this is for very old hardware.
    # Removal in 30 days

  • sys-auth/pam_keystore-0.1.3::calculate (masked by: package.mask)
    /usr/portage/profiles/package.mask:
    # Diego E. Pettenò flameeyes@gmail.com (09 Oct 2009)
    # Untested yet; documented only in Russian, help is appreciated.

For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.

Вы с профилем и USE-флагами что делали?
Где-то перемудрили, вот блокировки пакетов и возникли.

Попробуйте сперва обновить мир.

eix-sync
emerge -uDNa world