Qemu, virt-manager, spice-gtk. The problem was, that there was no sound from Virtual machine, if we don't use pulseaudio (but gstreamer instead). It was discussed at upstream bugzilla -> https://bugs.freedesktop.org/show_bug.cgi?id=93544 So, the issue is, that we need >=media-libs/gst-plugins-good-1.4.5 as dependency for net-misc/spice-gtk (USE="gstreamer -pulseaudio") to hear sound. Reproducible: Always
commit e608ae94ea5745193df84b08447598186d859dff Author: Matthias Maier <tamiko@gentoo.org> Date: Sun May 1 15:05:23 2016 -0500 net-misc/spice-gtk: add missing dependency on media-libs/gst-plugins-good, bug #571372 Package-Manager: portage-2.2.26