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

Calculating dependencies ... done!
Dependency resolution took 1.10 s (backtrack: 0/20).

[ebuild  N     ] acct-group/at-0-r2::gentoo  0 KiB
[ebuild  N     ] acct-user/at-0-r2::gentoo  0 KiB
[ebuild  N     ] sys-process/at-3.2.5-r2::gentoo  USE="pam (-selinux)" 130 KiB
[ebuild  N     ] dev-perl/Schedule-At-1.150.0-r3::gentoo  USE="-test" PERL_FEATURES="ithreads (-debug) -quadmath" 8 KiB

Total: 4 packages (4 new), Size of downloads: 138 KiB