ALICE software on ArchLinux is supported on a best effort basis. There is no guarantee that software builds or runs correctly. Support requests might have low priority.
With root permissions, i.e. sudo or as root install the prerequisites using:
pacman -S git python3 python-pip which gcc \
make gcc-fortran \
base-devel libxpm libxft glu gsl \
libuv tbb xerces-c re2 libwebsockets grpcYou are now ready to start building ALICE software