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

Calculating dependencies ... done!
Dependency resolution took 1.14 s (backtrack: 0/20).

[ebuild  N     ] media-libs/libogg-1.3.6::gentoo  USE="-static-libs" 430 KiB
[ebuild  N     ] media-libs/sheenbidi-3.0.0:0/3::gentoo  USE="-test" 2559 KiB
[ebuild  N     ] net-libs/mbedtls-2.28.10:0/7.14.1::gentoo  USE="threads -cmac -doc -havege -programs -static-libs -test -zlib" CPU_FLAGS_X86="sse2" 3408 KiB
[ebuild  N     ] media-libs/flac-1.5.0:0/11-14::gentoo  USE="cxx -debug -ogg -static-libs" CPU_FLAGS_X86="avx avx2" 1054 KiB
[ebuild  N     ] media-libs/libvorbis-1.3.7-r2::gentoo  USE="-static-libs -test" 1176 KiB
[ebuild  N     ] x11-libs/libXcursor-1.2.3::gentoo  USE="-doc" 286 KiB
[ebuild  N     ] x11-libs/xcb-util-0.4.1::gentoo  262 KiB
[ebuild  N     ] x11-libs/xcb-util-image-0.4.1::gentoo  283 KiB
[ebuild  N     ] media-libs/libsfml-3.1.0-r1:0/3.1::gentoo  USE="-doc -examples -test" 6207 KiB

Total: 9 packages (9 new), Size of downloads: 15661 KiB