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

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] sci-libs/gsl-2.7.1-r2:0/27::gentoo  USE="deprecated -cblas-external -static-libs" 7346 KiB

Total: 1 package (1 new), Size of downloads: 7346 KiB