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

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] app-arch/cpio-2.15::gentoo  USE="nls" 1613 KiB
[ebuild  N     ] app-alternatives/cpio-0::gentoo  USE="gnu (split-usr) -libarchive" 0 KiB
[ebuild  N     ] sys-kernel/rt-sources-5.10.239_p133:5.10.239_p133::gentoo  USE="-build -deblob -symlink -vanilla" 120635 KiB

Total: 3 packages (3 new), Size of downloads: 122248 KiB