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

Calculating dependencies ... done!
Dependency resolution took 1.51 s (backtrack: 0/20).

[ebuild     UD ] sys-kernel/linux-headers-4.19-r1::gentoo [6.19::gentoo] USE="-headers-only" 7774 KiB

Total: 1 package (1 downgrade), Size of downloads: 7774 KiB