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

Calculating dependencies ... done!
Dependency resolution took 1.50 s (backtrack: 0/20).

[ebuild     UD ] sys-apps/diffutils-3.10::gentoo [3.12::gentoo] USE="nls -verify-sig" 1587 KiB

Total: 1 package (1 downgrade), Size of downloads: 1587 KiB