Emerge

calculate package.use # emerge -av net-misc/networkmanager
!!! Found 2 make.conf files, using both '/etc/make.conf' and '/etc/portage/make.conf'


!!! Timed out while closing connection to binhost

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

Calculating dependencies... done!
[binary  N     ] sys-fs/udev-204  USE="acl firmware-loader gudev hwdb keymap kmod openrc -doc -introspection (-selinux) -static-libs" 0 kB
[binary  N     ] virtual/udev-200  USE="gudev hwdb keymap kmod -introspection (-selinux) -static-libs" 9 kB
[binary  N     ] sys-fs/udev-init-scripts-26  29 kB
[ebuild  N     ] net-misc/networkmanager-0.9.6.4-r2::calculate  USE="bluetooth connection-sharing dhcpcd introspection modemmanager nss ppp systemd wext wimax -avahi -consolekit -dhclient -doc -gnutls -resolvconf -vala" 1,923 kB
[blocks B      ] sys-fs/udev ("sys-fs/udev" is blocking sys-apps/systemd-204)
[blocks B      ] sys-apps/systemd ("sys-apps/systemd" is blocking sys-fs/udev-204)

Total: 4 packages (4 new, 3 binaries), Size of downloads: 1,960 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.

  (sys-apps/systemd-204::gentoo, installed) pulled in by
    >=sys-apps/systemd-31 required by (net-misc/networkmanager-0.9.6.4-r2::calculate, ebuild scheduled for merge)

  (sys-fs/udev-204::gentoo, binary scheduled for merge) pulled in by
    >=sys-fs/udev-200[gudev,hwdb,keymap,kmod] required by (virtual/udev-200::gentoo, binary 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