The following commands allow you to install CMake, .Net, and the dependencies required for Arcane (as well as the optional dependencies TBB, HDF5, and ParMetis):

sudo pacman -Syu
sudo pacman -S gcc cmake python git gcc-fortran glib2 libxml2 hdf5-openmpi wget tbb dotnet-sdk aspnet-runtime aspnet-targeting-pack
yay -S aur/parmetis

Prerequisites Compilation