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

Calculating dependencies ... done!
Dependency resolution took 0.97 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/aws-c-common-1.0.3:0/1.0::gentoo  USE="-test" 641 KiB
[ebuild  N     ] dev-libs/aws-c-compression-0.3.1:0/1::gentoo  USE="-test" 37 KiB

Total: 2 packages (2 new), Size of downloads: 677 KiB