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

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

[ebuild   R    ] dev-libs/json-c-0.18:0/5.1::gentoo  USE="threads -doc -static-libs -test" CPU_FLAGS_X86="rdrand" 393 KiB

Total: 1 package (1 reinstall), Size of downloads: 393 KiB