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

Calculating dependencies ... done!
Dependency resolution took 1.06 s (backtrack: 0/20).

[ebuild  N     ] x11-libs/libpciaccess-0.19::gentoo  USE="zlib -static-libs" 64 KiB
[ebuild  N     ] sys-apps/hwloc-2.12.2:0/15::gentoo  USE="X cairo cpuid pci -cuda -debug -doc -l0 -nvml -rocm (-selinux) -static-libs -svg -udev -valgrind -xml" VIDEO_CARDS="-nvidia" 5504 KiB
[ebuild  N     ] sys-cluster/openmpi-4.1.6-r1::gentoo  USE="-cma -cuda -cxx -fortran -libompitrace -peruse -romio -valgrind" OPENMPI_FABRICS="-knem -ofed" OPENMPI_OFED_FEATURES="-control-hdr-padding -dynamic-sl -rdmacm -udcm" OPENMPI_RM="-pbs (-slurm)" 9783 KiB

Total: 3 packages (3 new), Size of downloads: 15350 KiB