emerge -pv unrar
These are the packages that would be merged, in order:
Calculating dependencies... done!
[ebuild N ] app-arch/unrar-3.8.5 133 kB
[blocks B ] app-arch/unrar-gpl ("app-arch/unrar-gpl" is blocking app-arch/unrar-3.8.5)
[blocks B ] app-arch/unrar ("app-arch/unrar" is blocking app-arch/unrar-gpl-0.0.1_p20080417)
Total: 1 package (1 new), Size of downloads: 133 kB
Conflict: 2 blocks (2 unsatisfied)
* Error: The above package list contains packages which cannot be
* installed at the same time on the same system.
('ebuild', '/', 'app-arch/unrar-3.8.5', 'merge') pulled in by
unrar
('installed', '/', 'app-arch/unrar-gpl-0.0.1_p20080417', 'nomerge') pulled in by
app-arch/unrar-gpl required by ('installed', '/', 'media-video/mplayer-1.0_rc2_p20090322', 'nomerge')
For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):
