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

Calculating dependencies ... done!
Dependency resolution took 1.05 s (backtrack: 0/20).

[ebuild  N     ] net-libs/mbedtls-2.28.10:0/7.14.1::gentoo  USE="threads -cmac -doc -havege -programs -static-libs -test -zlib" CPU_FLAGS_X86="sse2" 3408 KiB
[ebuild  N     ] dev-scheme/gauche-0.9.15-r1:0/0.98::gentoo  USE="ipv6 -test" 9224 KiB

Total: 2 packages (2 new), Size of downloads: 12631 KiB