ip-10-226-66-16 ~ # emerge -pav =dev-db/mysql-5.5.19

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

Calculating dependencies... done!
[ebuild  N     ] dev-db/mysql-init-scripts-2.0_pre1-r2  0 kB
[ebuild  N     ] dev-perl/Net-Daemon-0.43  28 kB
[ebuild  N     ] perl-core/Storable-2.20  174 kB
[ebuild  N     ] perl-core/File-Spec-3.31  132 kB
[ebuild  N     ] perl-core/Sys-Syslog-0.290.0  78 kB
[ebuild  N     ] app-arch/libarchive-2.8.4-r1  USE="acl bzip2 lzma zlib -expat -static -static-libs -xattr" 1,468 kB
[ebuild  N     ] virtual/perl-Storable-2.20  0 kB
[ebuild  N     ] virtual/perl-File-Spec-3.31  0 kB
[ebuild  N     ] virtual/perl-Sys-Syslog-0.290.0  0 kB
[ebuild  N     ] dev-util/cmake-2.8.6-r4  USE="ncurses -emacs -qt4 -test -vim-syntax" 5,454 kB
[ebuild  N     ] dev-perl/PlRPC-0.202.0  18 kB
[ebuild  N     ] dev-perl/DBI-1.615  USE="-test" 558 kB
[ebuild  N    #] dev-db/mysql-5.5.19  USE="berkdb community perl ssl -cluster -debug -embedded -extraengine -latin1 -max-idx-128 -minimal -profiling (-selinux) -static -systemtap -test" 25,411 kB
[ebuild  N    #] virtual/mysql-5.5  USE="-embedded -minimal -static" 0 kB
[ebuild  N     ] dev-db/mysql-5.1.56  USE="community perl ssl -big-tables -cluster -debug -embedded -extraengine -latin1 -max-idx-128 -minimal -pbxt -profiling (-selinux) -static -test -xtradb" 25,496 kB
[ebuild  N     ] virtual/mysql-5.1  USE="-embedded -minimal -static" 0 kB
[ebuild  N     ] dev-perl/DBD-mysql-4.01.7  130 kB

Total: 17 packages (17 new), Size of downloads: 58,944 kB

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

dev-db/mysql:0

  (dev-db/mysql-5.1.56::gentoo, ebuild scheduled for merge) pulled in by
    =dev-db/mysql-5.1*[embedded=,minimal=,static=] required by (virtual/mysql-5.1::gentoo, ebuild scheduled for merge)

  (dev-db/mysql-5.5.19::gentoo, ebuild scheduled for merge) pulled in by
    =dev-db/mysql-5.5.19
    =dev-db/mysql-5.5*[embedded=,minimal=,static=] required by (virtual/mysql-5.5::gentoo, ebuild scheduled for merge)

virtual/mysql:0

  (virtual/mysql-5.1::gentoo, ebuild scheduled for merge) pulled in by
    =virtual/mysql-5.1 required by (dev-perl/DBD-mysql-4.01.7::gentoo, ebuild scheduled for merge)
    (and 1 more with the same problem)

  (virtual/mysql-5.5::gentoo, ebuild scheduled for merge) pulled in by
    =virtual/mysql-5.5 required by (dev-db/mysql-5.5.19::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. You may want to try a larger value of
the --backtrack option, such as --backtrack=30, in order to see if
that will solve this conflict automatically.

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


The following mask changes are necessary to proceed:
#required by dev-db/mysql-5.5.19, required by =dev-db/mysql-5.5.19 (argument)
# /usr/portage/profiles/package.mask:
# Jorge Manuel B. S. Vicetto <jmbsvicetto@gentoo.org> (28 Jul 2011)
# A new update of the mysql / mariadb mask
# Robin H. Johnson <robbat2@gentoo.org> (01 Feb 2010)
# Mask 5.5/6.0 series that are alpha and and crazy experimental.
# Mask 5.2/5.3 virtual that exists in the overlay as well (it is MariaDB only)
>=virtual/mysql-5.5
#required by virtual/mysql-5.5
# /usr/portage/profiles/package.mask:
# Jorge Manuel B. S. Vicetto <jmbsvicetto@gentoo.org> (28 Jul 2011)
# A new update of the mysql / mariadb mask
# Robin H. Johnson <robbat2@gentoo.org> (01 Feb 2010)
# Mask 5.5/6.0 series that are alpha and and crazy experimental.
# Mask 5.2/5.3 virtual that exists in the overlay as well (it is MariaDB only)
>=dev-db/mysql-5.5.19

NOTE: This --autounmask behavior can be disabled by setting
      EMERGE_DEFAULT_OPTS="--autounmask=n" in make.conf.