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

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] sci-libs/htslib-1.23.1:0/3::gentoo  USE="bzip2 lzma -curl" 4871 KiB
[ebuild  N     ] sci-biology/kallisto-0.46.2-r1::gentoo  USE="-hdf5 -test" 2631 KiB

Total: 2 packages (2 new), Size of downloads: 7501 KiB