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

Calculating dependencies ... done!
Dependency resolution took 1.43 s (backtrack: 0/20).

[ebuild  N     ] media-libs/libogg-1.3.6::gentoo  USE="-static-libs" 430 KiB
[ebuild  N     ] media-sound/fluid-soundfont-3.1::gentoo  USE="-timidity" 131676 KiB
[ebuild  N     ] media-libs/alsa-topology-conf-1.2.5.1-r1::gentoo  USE="-verify-sig" 12 KiB
[ebuild  N     ] media-libs/alsa-ucm-conf-1.2.16.1::gentoo  USE="-verify-sig" 83 KiB
[ebuild  N     ] media-libs/alsa-lib-1.2.16.1::gentoo  USE="python -debug -doc -verify-sig" PYTHON_SINGLE_TARGET="python3_14 -python3_12 -python3_13 (-python3_15)" 1104 KiB
[ebuild  N     ] app-eselect/eselect-mpg123-0.1-r1::gentoo  0 KiB
[ebuild  N     ] media-libs/opus-1.6.1::gentoo  USE="-custom-modes -debug -deep-plc -doc -dred -hardened -osce -static-libs -test" CPU_FLAGS_X86="sse" 10228 KiB
[ebuild  N     ] dev-libs/double-conversion-3.4.0:0/3::gentoo  USE="-test" 6871 KiB
[ebuild  N     ] dev-libs/md4c-0.6.0::gentoo  USE="md2html -test" 263 KiB
[ebuild  N     ] sys-libs/mtdev-1.1.7::gentoo  295 KiB
[ebuild  N     ] x11-misc/xkeyboard-config-2.48::gentoo  USE="-test" 931 KiB
[ebuild  N     ] media-sound/mpg123-base-1.33.7::gentoo  USE="alsa ipv6 (-coreaudio) -int-quality -jack -nas -oss -portaudio -pulseaudio -sdl -verify-sig" CPU_FLAGS_X86="sse (-3dnow) (-3dnowext) (-mmx)" 1100 KiB
[ebuild  N     ] media-libs/libvorbis-1.3.7-r2::gentoo  USE="-static-libs -test" 1176 KiB
[ebuild  N     ] x11-libs/xcb-util-renderutil-0.3.10::gentoo  256 KiB
[ebuild  N     ] media-libs/libmodplug-0.8.9.1::gentoo  234 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-sound/lame-3.100-r3::gentoo  USE="frontend -debug -mp3rtp -sndfile -static-libs" CPU_FLAGS_X86="(-mmx)" 1489 KiB
[ebuild  N     ] x11-libs/libXcursor-1.2.3::gentoo  USE="-doc" 286 KiB
[ebuild  N     ] x11-libs/libxkbcommon-1.13.2::gentoo  USE="X -doc -static-libs -test -tools -wayland" 1215 KiB
[ebuild  N     ] x11-libs/xcb-util-wm-0.4.2::gentoo  279 KiB
[ebuild  N     ] dev-libs/libevdev-1.13.7::gentoo  USE="-doc -test" 462 KiB
[ebuild  N     ] x11-libs/xcb-util-0.4.1::gentoo  262 KiB
[ebuild  N     ] media-libs/libsdl2-2.32.10::gentoo  USE="X alsa dbus haptic joystick opengl sound video (-aqua) (-custom-cflags) -doc -fcitx -gles1 -gles2 -ibus -jack -kms -libsamplerate -nas -oss -pipewire -pulseaudio -sndio -static-libs -test -udev -vulkan -wayland -xscreensaver" CPU_FLAGS_X86="mmx sse sse2 sse3 -3dnow" 7452 KiB
[ebuild  N     ] x11-libs/xcb-util-image-0.4.1::gentoo  283 KiB
[ebuild  N     ] media-libs/libsndfile-1.2.2-r2::gentoo  USE="alsa sqlite -minimal -test" 714 KiB
[ebuild  N     ] dev-libs/libinput-1.32.0:0/10::gentoo  USE="-doc -lua -test" INPUT_DEVICES="-wacom" LUA_SINGLE_TARGET="lua5-4" 944 KiB
[ebuild  N     ] media-sound/fluidsynth-2.5.7-r1:0/3::gentoo  USE="alsa dbus ipv6 openmp readline sndfile threads -debug -doc -jack -ladspa -oss -pipewire -portaudio -pulseaudio -sdl (-systemd)" 2124 KiB
[ebuild  N     ] x11-libs/xcb-util-cursor-0.1.6::gentoo  267 KiB
[ebuild  N     ] media-libs/sdl2-mixer-2.8.2-r1::gentoo  USE="fluidsynth midi mod modplug mp3 vorbis wav -flac -gme -opus -playtools -stb -timidity -tremor -wavpack -xmp" 5861 KiB
[ebuild  N     ] dev-qt/qtbase-6.11.2-r2:6/6.11.2::gentoo  USE="X concurrent dbus gui libinput network nls opengl sql sqlite ssl udev widgets xml (zstd) -accessibility -brotli -cups -custom-cflags -eglfs -evdev -gles2-only -gssapi -gtk -icu -io-uring (-journald) -libproxy -mysql -oci8 -odbc -postgres -renderdoc -sctp -syslog -test -tslib -vulkan -wayland" 49398 KiB
[ebuild  N     ] dev-qt/qttools-6.11.2:6/6.11.2::gentoo  USE="assistant linguist opengl qdbus widgets (zstd) -custom-cflags -designer -distancefieldgenerator -gles2-only -kmap2qmap -pixeltool -qdoc -qml -qmlls -qtattributionsscanner -qtdiag -qtplugininfo -vulkan" LLVM_SLOT="22 -17 -18 -19 -20 -21" 9992 KiB
[ebuild  N     ] dev-qt/qttranslations-6.11.2:6/6.11.2::gentoo  USE="-custom-cflags" 1652 KiB
[ebuild  N     ] games-strategy/freeciv-3.1.4::gentoo  USE="nls qt6 readline server sound system-lua -dedicated -gtk3 -gtk4 (-json) -mapimg -modpack -mysql -rule-editor -sdl -web-server" LUA_SINGLE_TARGET="lua5-4" 125894 KiB

Total: 33 packages (33 new), Size of downloads: 364272 KiB

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by games-strategy/freeciv-3.1.4::gentoo[sound,-dedicated]
# required by =games-strategy/freeciv-3.1.4 (argument)
>=media-libs/sdl2-mixer-2.8.2-r1 vorbis