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

Calculating dependencies ... done!
Dependency resolution took 1.40 s (backtrack: 0/20).

[ebuild  N     ] x11-misc/xkeyboard-config-2.48::gentoo  USE="-test" 931 KiB
[ebuild  N     ] media-libs/glm-1.0.3::gentoo  USE="-test" CPU_FLAGS_X86="avx avx2 sse2 sse3 sse4_1 sse4_2 ssse3" 4490 KiB
[ebuild  N     ] dev-cpp/nlohmann_json-3.12.0-r1::gentoo  USE="-test" 9452 KiB
[ebuild  N     ] dev-libs/yyjson-0.13.0:0/0.13::gentoo  USE="-doc -test" 1604 KiB
[ebuild  N     ] dev-util/vulkan-headers-1.4.363.0::gentoo  USE="-test" 3337 KiB
[ebuild  N     ] sys-libs/mtdev-1.1.7::gentoo  295 KiB
[ebuild  N     ] dev-util/wayland-scanner-1.26.0::gentoo  599 KiB
[ebuild  N     ] dev-libs/libevdev-1.13.7::gentoo  USE="-doc -test" 462 KiB
[ebuild  N     ] x11-libs/libxkbcommon-1.13.2::gentoo  USE="X -doc -static-libs -test -tools -wayland" 1215 KiB
[ebuild  N     ] x11-libs/libxkbfile-1.2.0::gentoo  57 KiB
[ebuild  N     ] media-libs/vulkan-loader-1.4.363.0::gentoo  USE="X -wayland" 1823 KiB
[ebuild  N     ] media-libs/libdisplay-info-0.4.0:0/4::gentoo  USE="-verify-sig" 117 KiB
[ebuild  N     ] sys-auth/seatd-0.9.3-r1:0/1::gentoo  USE="-builtin -elogind (-selinux) -server (-systemd)" 42 KiB
[ebuild  N     ] x11-libs/xcb-util-renderutil-0.3.10::gentoo  256 KiB
[ebuild  N     ] x11-libs/xcb-util-wm-0.4.2::gentoo  279 KiB
[ebuild  N     ] media-fonts/font-util-1.4.2::gentoo  150 KiB
[ebuild  N     ] media-libs/libepoxy-1.5.10-r3::gentoo  USE="X -test" 325 KiB
[ebuild  N     ] x11-libs/libxcvt-0.1.3::gentoo  10 KiB
[ebuild  N     ] x11-libs/libXfont2-2.0.9::gentoo  USE="bzip2 truetype -doc" 468 KiB
[ebuild  N     ] dev-libs/wayland-protocols-1.49::gentoo  USE="-test" 148 KiB
[ebuild  N     ] dev-libs/wayland-1.26.0::gentoo  USE="-doc (-selinux) -test" 0 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     ] x11-apps/xkbcomp-1.5.0-r2::gentoo  243 KiB
[ebuild  N     ] gui-libs/wf-config-0.10.0:0/0.10::gentoo  USE="-test" 43 KiB
[ebuild  N     ] x11-base/xwayland-24.1.14::gentoo  USE="-libei (-selinux) (-systemd) -test -unwind -xcsecurity" 1278 KiB
[ebuild  N     ] gui-libs/wlroots-0.19.2:0.19::gentoo  USE="X drm libinput session x11-backend -lcms -liftoff -verify-sig -vulkan -xcb-errors" 656 KiB
[ebuild  N     ] gui-wm/wayfire-0.10.1-r1:0/0.10::gentoo  USE="X dbus gles3 openmp -test" 920 KiB

Total: 27 packages (27 new), Size of downloads: 30130 KiB

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by gui-wm/wayfire-0.10.1-r1::gentoo
# required by =gui-wm/wayfire-0.10.1-r1 (argument)
>=gui-libs/wlroots-0.19.2:0.19 x11-backend