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

Calculating dependencies ... done!
Dependency resolution took 1.03 s (backtrack: 0/20).

[ebuild   R    ] dev-perl/Module-Build-0.423.400-r5::gentoo  USE="-test" PERL_FEATURES="ithreads (-debug) -quadmath" 305 KiB

Total: 1 package (1 reinstall), Size of downloads: 305 KiB