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

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

[ebuild  N     ] sci-libs/gsl-2.7.1-r3:0/27::gentoo  USE="deprecated -cblas-external -static-libs" 7346 KiB
[ebuild  N     ] app-crypt/dieharder-3.31.1-r4::gentoo  USE="-doc" 1123 KiB

Total: 2 packages (2 new), Size of downloads: 8468 KiB