Bugzilla Bug 159087

>>> Completed installing prboom-2.4.7 into /var/tmp/portage/prboom-2.4.7/image/

man:
gzipping man page: boom.cfg.5
gzipping man page: prboom-game-server.6
gzipping man page: prboom.6
strip: i686-pc-linux-gnu-strip --strip-unneeded
   usr/games/bin/prboom
   usr/games/bin/prboom-game-server
* checking 19 files for package collisions
existing file /usr/share/man/man5/boom.cfg.5.gz is not owned by this package
* spent 0.0241708755493 seconds checking for file collisions
* This package is blocked because it wants to overwrite
* files belonging to other packages (see messages above).
* If you have no clue what this is all about report it
* as a bug for this package on http://bugs.gentoo.org

package games-fps/prboom-2.4.7 NOT merged

No package files given... Grabbing a set.
>>> Regenerating /etc/ld.so.cache...
velbloud ~ # qfile /usr/share/man/man5/boom.cfg.5.gz
games-fps/lsdldoom (/usr/share/man/man5/boom.cfg.5.gz)
velbloud ~ # emerge -pv lsdldoom prboom

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

Calculating dependencies... done!
[ebuild   R   ] games-fps/lsdldoom-1.4.4.4  0 kB
[ebuild  N    ] games-fps/prboom-2.4.7  USE="opengl" 0 kB

Total size of downloads: 0 kB

Fixed by adding blockers... enjoy...