I've got error:
tux ~ # emerge @preserved-rebuild
* IMPORTANT: 8 news items need reading for repository 'gentoo'.
* Use eselect news read to view new items.
Calculating dependencies... done!
[ebuild R ] dev-libs/botan-1.10.17
[ebuild U ] media-gfx/imagemagick-7.0.7.6 [6.9.9.0]
[ebuild R ] dev-python/pillow-4.2.1-r1
[ebuild U ] media-libs/gst-plugins-base-1.12.3 [1.10.5]
[ebuild U ] dev-qt/qtgui-5.9.2 [5.7.1-r1] USE="libinput* -vnc%"
[ebuild R ] media-video/ffmpeg-3.3.4
[ebuild U ] dev-qt/qtwidgets-5.9.2 [5.7.1] USE="gtk%*"
[ebuild U ] media-libs/gst-plugins-ugly-1.12.3 [1.10.5]
[ebuild U ] dev-qt/qtdeclarative-5.9.2 [5.7.1]
[ebuild U ] dev-qt/qtprintsupport-5.9.2 [5.7.1]
[ebuild U ] media-video/vlc-2.2.6-r2 [2.2.6] USE="qt5*"
[ebuild U ] media-plugins/gst-plugins-x264-1.12.3 [1.10.5]
[ebuild U ] dev-qt/qtwebchannel-5.9.2 [5.7.1]
[ebuild R ] net-analyzer/wireshark-2.4.2
[ebuild U ] xfce-base/xfwm4-4.13.0-r1 [4.12.3-r1] USE="opengl%*
-xpresent%"
[ebuild U ] app-editors/vim-8.0.1188 [8.0.0386] USE="terminal%*"
PYTHON_SINGLE_TARGET="python3_4%* -python2_7% -python3_5% -python3_6%"
[ebuild U ] dev-qt/qtwebengine-5.9.2 [5.7.1-r2]
[ebuild R ] dev-db/postgresql-9.6.5-r1
[ebuild U ] media-video/obs-studio-20.0.1-r1 [20.0.1]
[ebuild U ] net-print/cups-filters-1.17.9 [1.16.4] USE="-pclm%"
[ebuild U ] media-gfx/graphviz-2.40.1 [2.38.0-r1]
[ebuild R ] www-servers/nginx-1.12.1
[ebuild R ] dev-lang/php-7.0.24
[ebuild R ] dev-db/mariadb-10.2.9
[blocks B ] =media-libs/gst-plugins-base-1.10.5:1.0[alsa?,ogg?,theora?,vorbis?,X?,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(-)?]
(>=media-libs/gst-plugins-base-1.10.5:1.0[alsa,ogg,vorbis,X,abi_x86_32(-),abi_x86_64(-)])
required by (media-plugins/gst-plugins-meta-1.10.5:1.0/1.0::gentoo,
installed)
>=media-libs/gst-plugins-base-1.12.3:1.0[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(-)?]
(>=media-libs/gst-plugins-base-1.12.3:1.0[abi_x86_32(-),abi_x86_64(-)])
required by (media-libs/gst-plugins-ugly-1.12.3:1.0/1.0::gentoo, ebuild
scheduled for merge)
>=media-libs/gst-plugins-base-1.4.5:1.0 required by
(media-video/vlc-2.2.6-r2:0/5-8::gentoo, ebuild scheduled for merge)
>=media-libs/gst-plugins-base-1.10.5:1.0[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(-)?]
(>=media-libs/gst-plugins-base-1.10.5:1.0[abi_x86_32(-),abi_x86_64(-)])
required by
(media-plugins/gst-plugins-cdparanoia-1.10.5:1.0/1.0::gentoo, installed)
>=media-libs/gst-plugins-base-1.10.5:1.0[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(-)?]
(>=media-libs/gst-plugins-base-1.10.5:1.0[abi_x86_32(-),abi_x86_64(-)])
required by (media-libs/gst-plugins-good-1.10.5:1.0/1.0::gentoo, installed)
>=media-libs/gst-plugins-base-1.10.5:1.0[X,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(-)?]
(>=media-libs/gst-plugins-base-1.10.5:1.0[X,abi_x86_32(-),abi_x86_64(-)])
required by (media-plugins/gst-plugins-v4l2-1.10.5:1.0/1.0::gentoo,
installed)
>=media-libs/gst-plugins-base-1.10.5:1.0[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(-)?]
(>=media-libs/gst-plugins-base-1.10.5:1.0[abi_x86_32(-),abi_x86_64
(-)]) required by
(media-plugins/gst-plugins-vaapi-1.10.5:1.0/1.0::gentoo, installed)
media-libs/gst-plugins-base:1.0 required by
(dev-qt/qtmultimedia-5.7.1:5/5.7::gentoo, installed)
>=media-libs/gst-plugins-base-1.10.5:1.0[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(-)?,introspection?]
(>=media-libs/gst-plugins-base-1.10.5:1.0[abi_x86_32(-),abi_x86_64(-),introspection])
required by (media-libs/gst-plugins-bad-1.10.5:1.0/1.0::gentoo, installed)
(media-libs/gst-plugins-bad-1.10.5:1.0/1.0::gentoo, installed) pulled
in by
>=media-libs/gst-plugins-bad-1.10.5:1.0[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(-)?]
(>=media-libs/gst-plugins-bad-1.10.5:1.0[abi_x86_32(-),abi_x86_64(-)])
required by (media-plugins/gst-plugins-dts-1.10.5:1.0/1.0::gentoo,
installed)
media-libs/gst-plugins-bad:1.0 required by
(dev-qt/qtmultimedia-5.7.1:5/5.7::gentoo, installed)
>=media-libs/gst-plugins-bad-1.10.5:1.0[opengl?,abi_x86_32(-