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

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/utfcpp-4.0.6::gentoo  USE="-test" 34 KiB
[ebuild  N     ] sci-misc/lttoolbox-3.7.1-r2:0/3::gentoo  171 KiB

Total: 2 packages (2 new), Size of downloads: 204 KiB