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

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

[ebuild     U  ] sys-process/htop-3.5.1::gentoo [3.4.1-r2::gentoo] USE="filecaps unicode -bfd% -caps -debug -delayacct -hwloc -llvm-libunwind -lm-sensors -openvz -unwind -vserver" 451 KiB

Total: 1 package (1 upgrade), Size of downloads: 451 KiB