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

Calculating dependencies ... done!
Dependency resolution took 1.54 s (backtrack: 0/20).

[ebuild  N     ] dev-build/pmake-1.111.3.3-r1::gentoo  290 KiB
[ebuild  NS    ] dev-lang/lua-5.3.6-r102:5.3::gentoo [5.4.8:5.4::gentoo] USE="deprecated readline" 529 KiB
[ebuild  N     ] www-servers/moonbridge-1.1.3-r1::gentoo  LUA_SINGLE_TARGET="lua5-3" 52 KiB

Total: 3 packages (2 new, 1 in new slot), Size of downloads: 870 KiB