Calculating dependencies... done!
[ebuild  N     ] sys-apps/systemd-215-r3:0/2  USE="acl firmware-loader gudev introspection kmod pam (policykit) seccomp -audit -cryptsetup -doc -elfutils -gcrypt -http (-kdbus) -lzma -python -qrcode (-selinux) (-ssl) {-test} -vanilla" ABI_X86="(64) (-32) (-x32)" PYTHON_SINGLE_TARGET="python2_7 (-python3_2) -python3_3 (-python3_4)" PYTHON_TARGETS="python2_7 python3_3 (-python3_2) (-python3_4)" 0 kB
[ebuild  N     ] sys-apps/gentoo-systemd-integration-4  0 kB
[ebuild     U  ] sys-apps/dbus-1.8.8 [1.6.12] USE="X systemd* -debug -doc (-selinux) -static-libs {-test}" ABI_X86="(64%*) (-32) (-x32)" 0 kB
[ebuild     U  ] virtual/udev-215 [200] USE="systemd%* (-gudev%*) (-hwdb%*) (-introspection%*) (-keymap%*) (-kmod%*) (-selinux%) (-static-libs%)" 0 kB
[ebuild     U  ] sys-apps/hwids-20141010 [20130329] USE="net%* pci%* udev usb%*" 0 kB
[ebuild  N     ] virtual/libgudev-215-r1  USE="introspection systemd -static-libs" ABI_X86="(64) (-32) (-x32)" 0 kB
[ebuild  N     ] virtual/libudev-215-r1:0/1  USE="systemd -static-libs" ABI_X86="(64) (-32) (-x32)" 0 kB
[ebuild  N     ] dev-libs/libgusb-0.1.6  USE="introspection -static-libs -vala" 0 kB
[ebuild  N     ] x11-misc/colord-1.2.1-r1:0/2  USE="gusb introspection (policykit) udev -examples -extra-print-profiles -scanner -systemd -vala" 0 kB
[ebuild     U  ] x11-libs/gtk+-3.12.2:3 [3.4.4:3] USE="X colord* cups introspection xinerama (-aqua) -cloudprint% -debug -examples {-test} -vim-syntax -wayland (-packagekit%)" 0 kB
[blocks B      ] sys-fs/udev ("sys-fs/udev" is blocking sys-apps/gentoo-systemd-integration-4, sys-apps/systemd-215-r3)
[blocks B      ] sys-apps/systemd ("sys-apps/systemd" is blocking sys-fs/udev-204)

Total: 10 packages (4 upgrades, 6 new), Size of downloads: 0 kB
Conflict: 2 blocks (2 unsatisfied)

!!! 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-200::gentoo, installed) pulled in by
    >=virtual/udev-197[gudev] required by (sys-power/upower-0.9.20-r2::gentoo, installed)
    virtual/udev:0/0=[gudev] required by (gnome-base/gvfs-1.12.3-r1::gentoo, installed)
    >=virtual/udev-197[gudev,hwdb] required by (sys-fs/udisks-2.1.0::gentoo, installed)
    >=virtual/udev-197[gudev,hwdb] required by (sys-fs/udisks-1.0.4-r5::gentoo, installed)

  (virtual/udev-215::gentoo, ebuild scheduled for merge) pulled in by
    =virtual/udev-215 required by (x11-base/xorg-server-1.13.4::gentoo, installed)
    >=virtual/udev-206 required by (sys-apps/hwids-20141010::gentoo, ebuild scheduled for merge)
    (and 16 more with the same problems)


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.


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

  (sys-fs/udev-204::gentoo, installed) pulled in by
    sys-fs/udev required by (app-misc/media-player-info-17::gentoo, installed)
    >=sys-fs/udev-200[gudev,hwdb,introspection,keymap,kmod] required by (virtual/udev-200::gentoo, installed)

  (sys-apps/systemd-215-r3::gentoo, ebuild scheduled for merge) pulled in by
    >=sys-apps/systemd-212-r5:0/2[abi_x86_32(-)?,abi_x86_64(-)?,abi_x86_x32(-)?,abi_mips_n32(-)?,abi_mips_n64(-)?,abi_mips_o32(-)?,abi_ppc_32(-)?,abi_ppc_64(-)?,abi_s390_32(-)?,abi_s390_64(-)?] (>=sys-apps/systemd-212-r5:0/2[abi_x86_64(-)]) required by (virtual/libudev-215-r1::gentoo, ebuild scheduled for merge)
    >=sys-apps/systemd-208:0 required by (virtual/udev-215::gentoo, ebuild scheduled for merge)
    >=sys-apps/systemd-212-r5:0/2[abi_x86_32(-)?,abi_x86_64(-)?,abi_x86_x32(-)?,abi_mips_n32(-)?,abi_mips_n64(-)?,abi_mips_o32(-)?,abi_ppc_32(-)?,abi_ppc_64(-)?,abi_s390_32(-)?,abi_s390_64(-)?,gudev,introspection?] (>=sys-apps/systemd-212-r5:0/2[abi_x86_64(-),gudev,introspection]) required by (virtual/libgudev-215-r1::gentoo, ebuild scheduled for merge)
    sys-apps/systemd:0= required by (sys-apps/dbus-1.8.8::gentoo, ebuild scheduled for merge)
    >=sys-apps/systemd-207 required by (sys-apps/gentoo-systemd-integration-4::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