Clearly-named env vars like these would be great, yes. If you do so, can you please keep the 5 macOS arch files homogeneous? (i.e. use libxc/libint in all of them, or none of them) Another question is: do we want to treat FFTW and Scalapack (for mpi builds) in the same way as libxc and libint? It seems to me it's the third "widely used" library that most users probably link with. At least, they're the ones we include in Homebrew.
cannot build against libxc
macOS arch file hardcodes /opt/local path
Remove project libmolsim
Cannot build on macOS 10.13
dc3dd fails with illegal instruction on macOS 10.13
Change of SHA256 sum for the latest release (1.4.2)
Fails to build with recent clang