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/libaio-0.3.113_p8::gentoo  USE="-static-libs -test" 74 KiB
[ebuild  N     ] dev-debug/strace-7.2::gentoo  USE="aio ncurses -elfutils -perl (-selinux) -static -test -unwind -verify-sig" 2745 KiB
[ebuild  N     ] app-misc/jail-2.0-r4::gentoo  31 KiB

Total: 3 packages (3 new), Size of downloads: 2849 KiB