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

Calculating dependencies ... done!
Dependency resolution took 0.98 s (backtrack: 0/20).

[ebuild  N     ] sci-libs/sundials-7.8.0:0/7::gentoo  USE="int64 openmp static-libs threads -doc -fortran -hypre -lapack -mpi -sparse -superlumt" 26030 KiB

Total: 1 package (1 new), Size of downloads: 26030 KiB