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

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

[ebuild  N     ] dev-libs/FXdiv-2020.12.09-r1::gentoo  USE="-test" 10 KiB
[ebuild  N     ] dev-libs/pthreadpool-2023.08.29::gentoo  USE="-test" 59 KiB

Total: 2 packages (2 new), Size of downloads: 68 KiB