bti

# emerge -vaDNu world

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

Calculating dependencies... done!
[ebuild  N     ] media-sound/cdparanoia-3.10.2-r4  USE="-static-libs" 0 kB
[ebuild  N    ~] app-admin/eselect-lib-bin-symlink-0.1.1  45 kB
[ebuild  N    ~] app-admin/eselect-cdparanoia-0.1  0 kB
[ebuild  N    ~] dev-libs/libcdio-paranoia-0.90  USE="cxx -static-libs {-test}" 607 kB
[ebuild  N     ] media-plugins/gst-plugins-cdparanoia-0.10.35:0.10  0 kB
[ebuild     U ~] media-libs/libcanberra-0.30-r1 [0.29] USE="alsa gnome gstreamer gtk sound udev -gtk3* -oss -pulseaudio -tdb" 312 kB
[blocks B      ] <media-sound/cdparanoia-3.10.2-r5 ("<media-sound/cdparanoia-3.10.2-r5" is blocking app-admin/eselect-cdparanoia-0.1)

Total: 6 packages (1 upgrade, 5 new), Size of downloads: 963 kB
Conflict: 1 block (1 unsatisfied)

 * Error: The above package list contains packages which cannot be
 * installed at the same time on the same system.

  (media-sound/cdparanoia-3.10.2-r4::gentoo, ebuild scheduled for merge) pulled in by
    >=media-sound/cdparanoia-3.10.2-r3 required by (media-plugins/gst-plugins-cdparanoia-0.10.35::gentoo, ebuild scheduled for merge)

  (app-admin/eselect-cdparanoia-0.1::gentoo, ebuild scheduled for merge) pulled in by
    app-admin/eselect-cdparanoia required by (dev-libs/libcdio-paranoia-0.90::gentoo, ebuild scheduled for merge)


For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):

http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked