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

Calculating dependencies ... done!
Dependency resolution took 0.99 s (backtrack: 0/20).

[ebuild  N     ] x11-apps/mesa-progs-9.0.0::gentoo  USE="X -gles2 -vulkan -wayland" 14492 KiB

Total: 1 package (1 new), Size of downloads: 14492 KiB