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

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] app-vim/airline-0.12::gentoo  120 KiB
[ebuild  N     ] app-vim/airline-themes-0_pre20181021::gentoo  38 KiB

Total: 2 packages (2 new), Size of downloads: 157 KiB