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

Calculating dependencies ... done!
Dependency resolution took 1.21 s (backtrack: 0/20).

[ebuild  N     ] virtual/fortran-0-r1::gentoo  USE="openmp" 0 KiB
[ebuild  N     ] sci-mathematics/plfit-1.0.1::gentoo  CPU_FLAGS_X86="sse sse2" 182 KiB
[ebuild  N     ] sci-libs/openblas-0.3.34::gentoo  USE="openmp -cpudetection -index64 -pthread -relapack -test" 24734 KiB
[ebuild  N     ] sci-libs/lapack-3.12.1-r2::gentoo  USE="deprecated flexiblas lapacke -doc -eselect-ldso -index64 -test" 7879 KiB
[ebuild  N     ] sci-libs/flexiblas-3.5.0::gentoo  USE="openblas openmp system-blas -blis -index64 -mkl -tbb -test" 80741 KiB
[ebuild  N     ] sci-libs/blas-lapack-aux-wrapper-6::gentoo  USE="-index64 -test" 10 KiB
[ebuild  N     ] virtual/blas-3.8-r1::gentoo  USE="flexiblas -eselect-ldso -index64" 0 KiB
[ebuild  N     ] virtual/lapack-3.10-r1::gentoo  USE="flexiblas -eselect-ldso -index64" 0 KiB
[ebuild  N     ] sci-libs/suitesparseconfig-7.12.2-r2:0/7::gentoo  USE="openmp -cuda" 93104 KiB
[ebuild  N     ] sci-libs/arpack-3.9.1::gentoo  USE="-examples -mpi" 997 KiB
[ebuild  N     ] sci-libs/amd-3.3.4-r1:0/3::gentoo  USE="-doc -fortran -test" 0 KiB
[ebuild  N     ] sci-libs/colamd-3.3.5-r1:0/3::gentoo  USE="-test" 0 KiB
[ebuild  N     ] sci-mathematics/glpk-5.0-r5:0/40::gentoo  USE="-doc -examples -mysql" 4036 KiB
[ebuild  N     ] dev-libs/igraph-0.10.15-r1::gentoo  USE="threads -debug -test" 4336 KiB

Total: 14 packages (14 new), Size of downloads: 216014 KiB