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

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] app-shells/tcsh-6.24.16::gentoo  USE="nls -man" 939 KiB
[ebuild  N     ] sci-biology/mummer-3.23-r1::gentoo  USE="-doc" 3087 KiB

Total: 2 packages (2 new), Size of downloads: 4025 KiB