larbalette thibaut # emerge -pv pulseaudio

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

Calculating dependencies... done!
[ebuild   R    ] media-sound/pulseaudio-8.0::gentoo  USE="X alsa alsa-plugin asyncns caps dbus gdbm glib ipv6 orc qt4 ssl tcpd udev webrtc-aec -bluetooth -doc -equalizer -gnome -gtk -jack (-libressl) -libsamplerate -lirc -native-headset (-neon) -ofono-headset (-oss) -realtime (-selinux) -sox (-system-wide) -systemd {-test} -xen -zeroconf" ABI_X86="(64) -32* (-x32)" 0 KiB

Total: 1 package (1 reinstall), Size of downloads: 0 KiB

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

media-sound/pulseaudio:0

  (media-sound/pulseaudio-8.0:0/0::gentoo, ebuild scheduled for merge) pulled in by
    media-sound/pulseaudio (Argument)

  (media-sound/pulseaudio-8.0:0/0::gentoo, installed) pulled in by
    media-sound/pulseaudio[abi_x86_32(-)] required by (net-im/skype-4.3.0.37-r6:0/0::gentoo, installed)
                                                                                                                        
    >=media-sound/pulseaudio-2.1-r1[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(-)?] required by (media-plugins/alsa-plugins-1.0.29:0/0::gentoo, installed)
                                                                                                                                                                                                                                                                                           


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 installed packages are masked:
- kde-plasma/kactivities-workspace-5.5.0::gentoo (masked by: package.mask)
/usr/portage/profiles/package.mask:
# Johannes Huber <johu@gentoo.org> (25 Jul 2016)
# Upstream temp workaround. No reverse dependencies.
# Removal in 30 days.

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