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

Calculating dependencies ... done!
Dependency resolution took 0.98 s (backtrack: 0/20).

[ebuild  N     ] www-servers/pound-4.22::gentoo  USE="-lua -tcmalloc -test" LUA_SINGLE_TARGET="-lua5-3 -lua5-4" 1115 KiB

Total: 1 package (1 new), Size of downloads: 1115 KiB